■v.. -#

\

AN

INTRODUCTION

TO

PHYSIOLOGICAL and SYSTEMATICAL

BOTANY.

BY

JAMES EDWARD SMITH, M.D. F.R.S.

PRESIDENT OF THE LINN^AN SOCIETY.

CONSIDER THE LILIES OF THE FIELD, HOW THEV GKOW.' ;

Hontion:

PRINTED FOR

F.ONGMAN, HURST, REES, AND ORME, PATERNOSTER ROW;

AND J. WHITE, FLEET-STREET.

1807.

Printed by Richard Taylor and Co. Shve-tai

TO

THE HONOURABLE AND RIGHT REVEREND

SHUTE,

LORD BISHOP OF DURHAM.
My Lord,

The circumstances which induce me
to solicit your Lordships protection for the
following pages are such, that I trust they
will ensure pardon for myself and more in-
dulgence for my performance than I might
expect, even from your Lordships usual
goodness towards me.

The contents of these pages were, in a very
unfinished state, honoured with the approba-
tion and encouragement of an excellent and
lamented lady, to whom they were destined to
be offered in their present less unworthy con-
dition. I should have been proud to have
sheltered them under her patronage, because
I have always found the most intelligent cri-
tics the most indulgent. Their general ten-
dency at least, as calculated to render an
interesting and useful science accessible, and

l/tWS?

IV DEDICATION.

in every point eligible^ to the more accom*
plished and refined of her own sex, could not
fail to have been approved by her, who knew
and exemplified so well the value and im-
portance of such pursuits, and their inesti-
mable effects upon the mind. These hopes %
which my late honoured friend and patroness
had, with her usual benignity, encouraged^
are now most unhappily defeated, and I
have no resource but in your Lordship, who
is no stranger to my pretensions, nor to my
sentiments, and in whom I have not now for
the first time to seek an able and enlightened
patron. I remain>

with the profoundest respect y
my Lord,
your Lordship's most obliged
and obedient servant,

J. E. SMITH.

Norwich,
Not. 15, 1807.

PREFACE.

After the many elementary works on
Botany which have appeared in various
languages, any new attempt of the same
kind may, at first sight, seem unnecessary.
But when we consider the rapid progress
of the science within a few years, in the
acquisition and determination of new
plants, and especially the discoveries and
improvements in vegetable physiology ;
when we reflect on the views with which
those fundamental works of Linnaeus, the
basis of all following ones, were com-
posed, and to whom they were addressed,
we must be aware of their unfitness for
purposes of general and popular utility^

VI PREFACE.

and that something else is wanting. If
we examine the mass of introductory
books on botany in this light, we shall
find them in some cases too elaborate and
intricate, in others too obscure and im-
perfect : they are also deficient in that
very pleasing and instructive part of bo-
tany, the anatomy and physiology of
plants. There are indeed works, such as
Rose's Elements of Botany, and Darwin's
Phytologia, with which no such faults can
be found. The former is a compendium
of Linnaean learning, the latter a store of
ingenious philosophy ; but they were de-
signed for philosophers, and are not cal-
culated for every reader. Linnaeus and
his scholars have generally written in La-
tin. They addressed themselves to phy-
sicians, to anatomists, to philosophers,
little thinking that thjeir science would
ever be the amusing pursuit of the young,
the elegant and the refined, or they would

PREFACE. vii

have treated the subject differently. It
appears to me, therefore, that an intro-
ductory publication is still desirable in
this country, on an original plan, easy,
comprehensive, and fit for general use,
and such were the reasons which first
prompted me to the undertaking.

When, however, I had proceeded a con-
siderable way in its execution, I found
that such a work might not only serve to
teach the first outlines of the science, but
that it might prove a vehicle for many ob-
servations, criticisms, and communications,
scarcely to be brought together on any
other plan; nor did it appear any objection
to the general use of the book, that, be-
sides its primary intention, it might be ca-
pable of leading into the depths of bota-
nical philosophy, whether physiological,
systematical, or critical, any student who
should be desirous of proceeding so far.
A volume of this size can indeed be but

VIU PREFACE.

elementary on subjects so extensive ; but
if it be clear and intelligible as far as it
goes, serving to indicate the scope of the
science of botany, and how any of its
branches may be cultivated further, my
purpose is answered. The subject has na-
turally led me to a particular criticism
of the Linmean system of arrangement,
which the public, it seems, has expected
from me. Without wasting any words on
those speculative and fanciful changes,
which the most ignorant may easily make,
in an artificial system; and without enter-
ing into controversy with the very few
competent writers who have proposed any
alterations ; I have simply stated the re-
sult of my own practical observations,
wishing by the light of experience to cor-
rect and to confirm what has been found
useful, rather than rashly to overthrow
what perhaps cannot on the whole be im-
provecL

PREFACE. IX

As the discriminating characters of the
Linnsean system are founded in nature
and fact, and depend upon parts essential
to every species of plant when in perfec-
tion ; and as the application of them to
practice is, above all other systems, easy
and intelligible ; I conceive nothing more
useful can be done than to perfect, upon
its own principles, any parts of this sy-
stem that experience may show to have
been originally defective. This is all I
presume to do. Speculative alterations
in an artificial system are endless, and
scarcely answer any more useful purpose
than changing the order of letters in an
alphabet. The philosophy of botanical
arrangement, or the study of the natural
affinities of plants, is quite another mat-
ter. But it would be as idle, while we
pursue this last-mentioned subject, so
deep and so intricate that its most able
cultivators are only learners, to Jay aside

X PREFACE.

the continual use of the Linnaean system,
as it would be for philologists and logi-
cians to slight the convenience, and in-
deed necessity, of the alphabet, and to
substitute the Chinese character in its
stead. If the following pages be found
to elucidate and to confirm this compa-
rison, I wish the student to keep it ever
in view.

The illustration of the Linnaean system
of classification, though essential to my
purpose, is however but a small part of
my aim. To explain and apply to prac-
tice those beautiful principles of method,
arrangement and discrimination, which
render botany not merely an amusement,
a motive for taking air and exercise, or an
assistance to many other arts and sciences;
but a school for the mental powers, an
alluring incitement for the young mind to
try its growing strength, and a confirma-
tion of- the most enlightened understand-

PREFACE. Xl

ino* in some of its sublimest most im-
portant truths. That every path tending to
ends so desirable may be accessible, I
have not confined myself to systematical
subjects, wide and various as they are,
but I have introduced the anatomy and
physiology of plants to the botanical stu-
dent, wishing to combine all these several
objects; so far at least that those who do
not cultivate them all, may be sensible of
the value of each in itself, and that no
disgraceful rivalship or contempt, the
offspring of ignorance, may be felt by
the pursuers of any to the prejudice of
the rest.

I have treated of physiological and
anatomical subjects in the first place, be-
cause a true knowledge of the structure
and parts of plants seems necessary to the
right understanding of botanical arrange-
ment; and I trust the most superficial
reader will here find enough for that pur-

Xli PREFACE.

pose, even though he should not be led to
pursue these subjects further by himself.
I have every where aimed at familiar il-
lustrations and examples, referring, as
much as possible, to plants of easy ac-
quisition. In the explanation of bota-
nical terms and characters, I have, be-
sides furnishing a new set of plates with
references to the body of the work, al-
ways cited a plant for my purpose by its
scientific name, with a reference to some
good and sufficient figure. For this end
I have generally used either my own
works English and Exotic Botany, all the
plates of which, as well as of the present
volume, are the performance of the same
excellent botanist as well as artist ; or
Curtis $ Magazine, much of which also
was drawn by Mr. Sowerby. I have
chosen these as the most comprehensive
and popular books, quoting others only
when these failed me, or when I had some

PREFACE, Xlli

particular end in view. If this treatise
should be adopted for general use in
schools or families, the teacher at least
will probably be furnished with those
works, and will accommodate their con-
tents to the use or the pupils. I am
aware of the want of a systematical En-
glish description of British plants, on the
principles of this Introduction ; but that
deficiency I hope as soon as possible' to
supply. In the mean while Dr. Wither-
ing^ work may serve the desired purpose,
attention being paid only to his original
descriptions, or to those quoted from
English writers. His index will atone
for the changes I cannot approve in his
system. Wherever my book may be found
deficient in the explanation of his or any
other terms, as I profess to retain only
what are necessary, or in some shape use-
ful, the Language of Botany^ by Pro-

XIV PREFACE*

fessor Martyn> will prove extremely ser-
viceable.

Having thus explained the use and in-
tention of the present work, perhaps a
few remarks on the recommendations of
the study of Botany, besides what have
already been suggested, may not here be
misplaced.

I shall not labour to prove how delight-
ful and instructive it is to

" Look through Nature up to Nature's God."

Neither, surely, need I demonstrate,
that if any judicious or improved use is to
be made of the natural bodies around us,
it must be expected from those who dis-
criminate their kinds and study their pro-
perties. Of the benefits of natural sci-
ence in the improvement of many arts,
no one doubts. Our food, our physic,
our luxuries are improved by it. By the
enquiries of the curious new acquisitions

PREFACE* XV

are made in remote countries, and our re-
sources of various kinds are augmented.
The skill of Linnaeus by the most simple
observation, founded however on scien-
tific principles, taught his countrymen to
destroy an insect, the Cantharis navalis,
which had cost the Swedish government
many thousand pounds a year by its ra-
vages on the timber of one dockyard only.
After its metamorphoses, and the season
when the fly laid its eggs, were known,
all its ravages were stopped by immersing
the timber in water during that period.
The same great observer, by his botanical
knowledge, detected the cause of a dread-
ful disease among; the horned cattle of the
north of Lapland, which had previously
been thought equally unaccountable and
irremediable, and of which he has given
an exquisite account in his Lapland tour,
as well as under Cicuta virosa, Engl. Bot.
/, 479, in his Flora Lapponica. One man

XVI * PREFACE.

in our days, by his scientific skill alone,
has given the bread-fruit to the West-
Indies, and his country justly honours his
character and pursuits* All this is ac-
knowledged. We are no longer in the in-
fancy of science, in which its utility, not
having been proved, might be doubted,
nor is it for this that I contend. I would
recommend botany for its own sake. I
have often alluded to its benefits as a
mental exercise, nor can any study exceed
it in raising curiosity, gratifying a taste for
beauty and ingenuity of contrivance, or
sharpening the powers of discrimination.
What then can be better adapted for
young persons ? The chief use of a great
part of our education is no other than
what I have just mentioned. The lan-
guages and the mathematics, however
valuable in themselves when acquired,
are even more so as they train the youth-
ful mind to thought and observation. In

PREFACE, XV11

Sweden Natural History is the study of
the schools, by which men rise to prefer-
ment; and there are no people with more
acute or better regulated minds than the
Swedes.

To those whose minds and understand-
ings are already formed, this study may
be recommended, independently of all
other considerations, as a ricji source of
innocent pleasure. Some people are ever
enquiring " what is the use" of any par-
ticular plant, by which they mean " what
food or physic, or what materials for the
painter or dyer does it afford ?" They look
on a beautiful flowery meadow with ad-
miration, only in proportion as it affords
nauseous drugs or salves. Others consider
a botanist with respect only as he may be
able to teach them some profitable im-
provement in tanning, or dyeing, by
which they may quickly grow rich, and
be then perhaps no longer of any use to

b

XVill PREFACE.

mankind or to themselves. They would
permit their children to study botany,
only because it might possibly lead to
professorships, or other lucrative prefer-
ment.

These views are not blameable, but
they are not the sole end of human ex-
istence. Is it not desirable to call the
soul from the feverish agitation of worldly
pursuits, to the contemplation of Divine
Wisdom in the beautiful economy of
Nature ? Is it not a privilege to walk with
God in the garden of creation, and hold
converse with his providence ? If such ele-
vated feelings do not lead to the study of
Nature, it cannot far be pursued without
rewarding the student by exciting them.

Rousseau, a great judge of the human
heart and observer of human manners,
has remarked, that " when^ science is
transplanted from the mountains and
woods into cities and worldly society, it

PREFACE. XIX

loses its genuine charms, and becomes a
source of envy, jealousy and rivalship."
This is still more true if it be cultivated
as a mere source of emolument/ But the
man who loves botany for its own sake
knows no such feelings, nor is he depen-
dent for happiness on situations or scenes
that favour their growth. He would find
himself neither solitary nor desolate, had
he no other companion than a " moun-
tain daisy," that " modest crimson-tipped
flower," so sweetly sung by one of Na-
ture's own poets. The humblest weed or
moss will ever afford him something to
examine or to illustrate, and a great deal
to admire. Introduce him to the magni-
ficence of a tropical forest, the enamelled
meadows of the Alps, or the wonders of
New Holland, and his thoughts will not
dwell much upon riches or literary ho-
nours, things that

<( Play round thehead, but come not near the heart."

b2

X$ PREFACE.

One idea is indeed worthy to mix in the
pure contemplation of Nature, the anti-
cipation of the pleasure we may have to
bestow 'on kindred minds with our own,
in sharing with them our discoveries and
our acquisitions. This is truly an object
worthy of a good man, the pleasure of
eammunicating virtuous disinterested
pleasure to those who have the same tastes
with ourselves ; or of guiding young inge-
nuous minds to worthy pursuits, and facili-
tating their acquisition of what we have
already obtained. If honours and re-
spectful consideration reward such mo-
tives, they flow from a pure source. The
<river and the receiver are alike invulne-
rable, as well as inaccessible, to " envy
jealousy or rivalship ". and may pardon
their attacks without an effort.

The natural history of animals, in many
respects even more interesting than botany
to man as an animated being, and more

PREFACE. XXI

striking in some of the phenomena which
it displays, is in other points less pleasing
to a tender and delicate mind. In botany
all is elegance and delight. No painful,
disgusting, unhealthy experiments or en-
quiries are to be made. Its pleasures
spring up under our feet, and, as we pur-
sue them, reward us with health and
serene satisfaction. None but the most
foolish or depraved could derive any
thing from it but what is beautiful, or
pollute its lovely scenery with unamiable
or unhallowed images. Those who do so,
either from corrupt taste or malicious de-
sign, can be compared only to the fiend
entering into the garden of Eden.

Let us turn from this odious picture
to the contemplation of Nature, ever new,
ever abundant in inexhaustible variety.
Whether we scrutinize the damp recesses
of woods in the wintry months, when the
numerous tribes of mosses are displaying

XX11 PREFACE.

their minute, but highly interesting struc-
ture ; whether we walk forth in the early
spring, when the ruby tips of the haw-
thorn-bush give the first sign of its ap-
proaching vegetation, or a little after,
when the violet welcomes us with its scent,
and the primrose with its beauty; whether
we contemplate in succession all the pro-
fuse flowery treasures of the summer, or
the more hidden secrets of Nature at the
season when fruits and seeds are forming ;
the most familiar objects, like old friends,
will always afford us something to study
and to admire in their characters, while
new discoveries will awaken a train of new
ideas. The yellow blossoms of the morn-
ing, that fold up their delicate leaves as
the day advances ; others that court and
sustain the full blaze of noon ; and the
pale night-scented tribe, which expand,
and diffuse their very sw r eet fragrance,
towards evening, will all please in their

PREFACE. XX1U

turn. Though spring is the season of
hope and novelty, to a naturalist more
especially, yet the wise provisions and
abundant resources of Nature, in the
close of the year, will yield an observing
mind no less pleasure, than the rich variety
of her autumnal tints afford to the ad-
mirers of her external charms. The more
we study the works of the Creator, the
more wisdom, beauty and harmony be-
come manifest, even to our limited ap-
prehensions ; and while we admire, it is
impossible not to adore.

(i Soft roll your incense, herbs, and fruits, and flowers,
In mingled clouds, to Him, whose sun exalts,
Whose breath perfumes you, and whose pencil paints !"

INTRODUCTION

TO

PHYSIOLOGICAL and SYSTEMATICAL

BOTANY.

CHAPTER I.

DISTINCTIONS BETWEEN ANIMALS, VE-
GETABLES AND FOSSILS.— ON THE
VITAL PRINCIPLE ESSENTIAL TO THE
TWO FORMER.

Those who with a philosophical eye have
contemplated the productions of Nature,
have all, by common consent, divided theiu
into three great classes, called the Animal,
the Vegetable, and the Mineral or Fossil
Kingdoms. These terms are still m jne-
ral use, and the most superficial observer

B

2 DISTINCTIONS BETWEEN ANIMALS

must be struck with their propriety. The
application of them seems at first sight per-
fectly easy, and in general it is so. Difficul-
ties occur to those only who look very deep-
ly into the subject.

Animals have an organized structure
which regularly unfolds itself, and is nou-
rished and supported by air and food ; they
consequently possess life, and are subject
to death; they are moreover endowed with
sensation, and with spontaneous, as well as
voluntary, motion.

Vegetables are organized, supported by
air and food, endowed with life and subject
to death as well as animals. They have in
some instances spontaneous, though we know
• not that they have voluntary, motion. They
are sensible to the action of nourishment, air,
and light, and either thrive or languish ac-
cording to the wholesome or hurtful applica-
tion of these stimulants. This is evident to all
who have ever seen a plant growing in a cli-
mate, soil, or situation, not suitable to it.
Those who have ever gathered a, rose, know
but too well how soon it withers ; and the

ANl> VEGETABLES.

familiar application of its fate to that of
human life and beauty, is not more striking
to the imagination than philosophically and
literally true. The sensitive plant is a more
astonishing example of the capability of
vegetables to be acted upon as living bodies.
Other instances of the same kind we shall
hereafter have occasion to mention.

The spontaneous movements of plants are
almost as readily to be observed as their
living principle. The general direction of
their branches,, and especially of the upper
surface of their leaves, though repeatedly
disturbed, to the light ; the unfolding and
closing of their flowers at stated times, or
according to favourable or unfavourable' cir-
cumstances, with some still, more curious,
particulars to be explained in the sequel of
this work, are actions undoubtedly depending
on their vital principle, and are performed
with the greater facility in proportion as that
principle is in its greatest vigour. Hence
arises a question whether Vegetables are
endowed with sensation. As they possess
life, irritability and motion, spontaneously
directing their organs to what is natural and

b 2

4 DISTINCTIONS BETWEEN ANIMALS

beneficial to them, and flourishing according
to their success in satisfying their wants,
may not the exercise of their vital functions
be attended with some degree of sensation,
however low, and some consequent share of
happiness? Such a supposition accords with
all the best ideas we can form of the Divine
Creator; nor could the consequent uneasiness
which plants must Buffer, no doubt in a very
low degree likewise, from the depredations
of animals, bear any comparison with their
enjoyment on the whole. However this may
be, the want of sensation is most certainly
not to be proved with regard to Vegetables,
and therefore of no use as a practical means
of distinguishing them, in doubtful cases,
from Animals.

Some philosophers* have made a loco-
motive power peculiarly characteristic of Ani-
mals, not being aware of the true nature of
those hali-animated beings called Corals and
Corallines, which are fixed, as immoveably
as any plants, to the bottom of the sea, while
indeed many living vegetables swim around

* JungiuSj Boerhaave, Ludwig and many others

AN'D VEGETABLES.

them, unattached to the soil, and nourished
by the water in which they float. Some*
have characterized Animals as nourished by
their internal, and Vegetables by their exter-
nal surface, the latter having no such thing as
an internal stomach. This is ingenious and
tolerably correct; but the proofs of it must
fail with respect to those minute and simply-
constructed animals the Polypes, and the
lower tribes of Worms, whose feelers, put
forth into the water, seem scarcely different
from roots seeking their food in the earth,
and some of which may he turned inside out,
.like a glove, without any disturbance of their
ordinary functions. The most satisfactory
flemark I have for a long time met with on
this difficult subject is that of M. Mirbel,
in his TraitS d f Anatomic et dc Phi/siologie
VSgltahs\^ work I shall often have occasion
to quote. He observes, voi. I. p: If), " that
plants alone, have a power of deriving nou-
rishment, though not indeed exclusively, from

* Dr. Alston, formerly professor of botany at Edin-
burgh.

f Published at Paris two or three years since, in two
vols Svo.

MINERAL KINGDOM.

inorganic matter, mere earths, salts or airs,
substances certainly incapable of serving as
food for any animals, the latter only feeding
on what is or has been organized matter,
either of a vegetable or animal nature. So
that it should seem to be the office of vege-
table life alone to transform dead matter
into organized living bodies/' This idea ap-
pears to me so just, that I have in vain sought
for any exception to it.

Let us however descend from these philo-
sophical speculations to purposes of practical
utility. It is sufficient for the young student
of Natural History to know, that in every
case in which he can be in doubt whether
he has found a plant or one of the lower orders
of animals, the simple experiment of burning
will decide the question. The smell of a
burnt bone, coralline, or other animal sub-
stance, is so peculiar that it can never be mis-
taken, nor does any known vegetable give
out the same odour.

The Mineral Kingdom can never be con-
founded with the other two. Fossils are
masses of mere dead unorganized matter,
subject to the laws of chemistry alone ; grow-

ON THE VITAL PR&CIPLE. 7

ing indeed, or increasing by the mechanical
addition of extraneous substances, or by the
laws of chemical attraction, but not fed by
nourishment taken into an organized struc-
ture. Their curious crystallization bears some
resemblance to organization, but performs
none of its functions, nor is any thing like a
vital principle to be found in this department
of Nature.

If it be asked what is this vital principle, so
essential to animals and vegetables, but of
which fossils are destitute, we must own our
complete ignorance. We know it, as we know
its Omnipotent Author, by its effects.

Perhaps in the fossil kingdom heat may
be equivalent to a vital principle ; but heat is
not the vital principle of organized bodies,
though probably a consequence of that prin-
ciple.

Living bodies of animals and plants produce
heat ; and this phenomenon lias not, I think,
been entirely explained on any chemical
principles, though in fossils the production of
heat is in most cases tolerably well accounted
for. In animals it seems to have the closest pos-
sible connexion with the vital energy. But the

$ OK TH# VITAL PRINCIPLE.

effects of this vital energy are still more stu-
pendous in the operations constantly going on in
every organized body, from our own elaborate
frame to the humblest moss or fungus. Those
different fluids, so fine and transparent, sepa-
rated from each other by membranes as fine,
which compose the eye, all retain their pro-
per situations (though each fluid individually
is perpetually removed and renewed) for sixty,
eighty, or a hundred years, or more, while life
remains. So do the infinitely small vessels of
an almost invisible insect, the fine and pellucid
tubes of a plant, all hold their destined fluids,
conveying or changing them according to
fixed laws, but never permitting them to run
into confusion, so long as the vital principle
animates their various forms. But no sooner
does death happen, than, without any alte-
ration of structure, any apparent change in
their material configuration, all is reversed.
The eve loses its. form and brightness; its
membranes let go their contents, which mix in
confu i ;n, and thenceforth yield to the laws of
chemistry alone. Just so it happens, sooner
or later, to the other parts of the animal as
■well as vegetable frame. Chemical changes,

ON THE VITAL PRINCIPLE. 9

putrefaction and destruction, immediately
follow the total privation of life, the import-
ance of which becomes instantly evident when
it is no more. I humbly conceive therefore,
that if the human understanding can, in any
case, flatter itself with obtaining, in the
natural world, a glimpse of the immediate
agency of the Deity, it is in the contempla-
tion of this vital principle > which seems inde-
pendent of material organization, and an
impulse of his own divine energy.

io

CHAPTER II.

BEFINITION OF NATURAL HISTORY, AND
PARTICULARLY BOTANY. OF THE GE-
NERAL TEXTURE OF PLANTS.

Natural History properly signifies that
study by which we learn to distinguish from
©ne another the natural bodies, whether Ani-
mal, Vegetable or Mineral, around us; to dis-
cover as much as possible their nature and pro-
perties, and especially their natural depen-
dence on each other in the general scale of
beings. In a more extensive sense it may
be said to teach their secondary properties,
or the various uses to which they have been>
or may be, converted, in the service of man-
kind or of other animals ; inasmuch as an ac-
quaintance with their natural qualities is our
only sure guide to a. knowledge of their arti^

DEFINITION OF BOTANY. ]J

ficial uses. But as this definition would in-
clude many arts and sciences, each of them
sufficient to occupy any common mind, as
Agriculture, Dietetics, Medicine, and many
others; it is sufficient for a philosophical na-
turalist to be acquainted with the general
principles upon which such arts and sciences
are founded.

That part of Natural History which con-
cerns plarits is called Botany, from Boravtf, the
Greek word for an herb or grass. It may be
divided into three branches; 1st, The phy-
siology of plants, or a knowledge of the struc-
ture and functions of their different parts; 2 dry,
The systematical arrangement and denomina-
tion of their several kinds; and odly, Their
(economical or medical properties. All these
objects should be kept in view by an intelli-
gent botanist. The two first are of essential
service to each other, and the last is only to
be pursued, with any certainty, by such as
are versed in the other two. The present
publication is intended to explain the funda-
mental principles of them all, with as much
practical illustration as may be necessary for
those who wish to become well acquainted

12 <GENERAL TEXTURE OF PLANTS.

with this delightful science. Botanv has one
advantage over many other useful and neces-
sary studies, that even its first beginnings are
pleasing and profitable, though pursued to
ever so small an exient ; the objects with
which it is conversant are in themselves
charming, and they become doubly so to
those who contemplate them with the addi-
tional s^nse, as it were, which science gives ;
the pursuit of these objects is an exercise no
less healthful to the body, than the observa-
tion of their laws and characters is to the
mind.

In studying the functions of the Vegetable
frame, we must constantly remember that it is
not merely a collection of tubes or vessels
holding: different fluids, but that it is endowed
h life, and consequently able not only to
imbibe particular fluids, but to alter their
nature according to certain laws, that is, to
form peculiar secretions. This is the exclusive
property of a living being. Animals secrete
milk and fat from food which has no resem-
blance to those substances; so Vegetables
secrete gum, sugar, and various resinous suh-
stances from the uniform juices of the earth,

GENERAL TEXTURE OP PLANTS. 13

or perhaps from mere water and air. The
most different and discordant fluids, sepa-
rated only by the finest film or membrane,
are, as we have already observed, kept per-
fectly distinct, while life remains; but no
sooner does the vital principle depart, than
secretion, as well as the due preservation of
what has been secreted, are both at an end,
and the principle of dissolution reigns abso-
lute.

Before we can examine the physiology of
vegetables, it is necessary to acquire some
idea of their structure.

JVIuch light has been thrown upon the
general texture of Vegetables by the micro-
scopic figures of Grew, Malpighi and others,
repeated by Dr. Thornton in his Illustration
of the Linnsean System, but more especially
by the recent observations and highly mag-
nified dissections of M. Mirbel. See his
Table of Vegetable Anatomy in the work
already mentioned. From preceding writers
we had learned the general tubular or vas-
cular structure of the vegetable body, and
the existence of some peculiar spirally-coated
vessels in many plants. On these slender

14 GENERAL TEXTURE OF PLANTS - .

foundations physiologists have, at their plea-
sure, constructed various theories, relative
to the motion of the sap, respiration and other
functions, presumed to be analogous to those
of animals. The anatomical observations of
Mirbel go further than those of Grew, &c.*
and it is necessary to give a short account of
his discoveries.

He finds, by the help of the highest mag-
nifying powers, that the vegetable body is a
continued mass of tubes and cells; the former
extended indefinitely, the latter frequently
and regularly interrupted by transverse par-
titions. These partitions being ranged alter-
nately in the corresponding cells, and each
cell increasing somewhat in diameter after its
first formation, except where restrained by
the transverse partitions, seems to account
for their hexagonal figure*. See Tab. \.f. a.
The membranous sides of all these cells and
tubes are very thin, more or less transparent,
often porous, variously perforated or torn.
Of the tubes, some are without any lateral per-
forations, f. b, at least for a considerable ex-

m

* In microscopic figures they are generally drawn
like circles intersecting each other.

GENERAL TEXT&RE OF PLANTS, IS

tent ; others pierced with holes ranged in a
close spiral line, f. c ; in others several of
these holes run together, as it were, into
interrupted spiral clefts, f. d ; and in some
those clefts are continued, so that the whole
tube, more or less, is cut into a spiral line,
f. ej which, in some young branches and ten-
der leaves, will unroll to a great extent, when
they are gently torn asunder. The cellular
texture especially is extended to every part
of the vegetable body, even into the thin
skin, called the cuticle, which covers every
external part, and into the fine hairs or down
which, in some instances, clothe the cuticle
itself.

Before we offer any thing upon the sup-
posed functions of these different organs,
we shall take a general view of the Vegetable
body, beginning at the external part and
proceeding inwards.

16

CHAPTER III.

OF THE CUTICLE OR EPIDERMIS.

Every part of a living plant is covered
with a skin or membrane called the cuticle,
which same denomination has been given
by anatomists to the scarf skin that covers
the animal body, protecting it from the
injuries of the air, and allowing of due absorp-
tion and perspiration through its pores.

There is the most striking analogy between
the animal and the vegetable cuticle. In the
former, it varies in thickness from the exqui-
sitely delicate film which covers the eye, to
the hard skin of the hand or foot, or the far
coarser covering of a Tortoise or Rhinoceros ;
in the latter it is equally delicate on the parts
of a flower, and scarcely less hard on the
leaves of the Pearly Aloe, or coarse on the
trunk of a Plane tree. In the numerous layers

OF THE CUTICLE OR EPIDERMIS, TJ

ci this membrane continually peeling off from
the Birch, we see a resemblance to the
scales which separate from the shell of a
Tortoise. By maceration, boiling, or putre-
faction, this part is separable from the plant
as well as from the animal, being, if not ab-
solutely incorruptible, much less prone to
decomposition than the parts it covers. The
vital principle, as far as we can judge, seems
to be extinct in it.

The cuticle admits of the passage of fluids
from within as well as from without, but in
a due and definite proportion in every plant :
consequently it must be porous ; and the mi-
croscope shows, what reason would teach us
to expect, that its pores are different in dif-
ferent kinds of plants. In very succulent
plants, as Aloes, a leaf of which being cut off
will lie for many weeks in the sun without
drying entirely, and yet when partly dry
will become plump again in a few hours if
plunged into water, the cuticle must be very
curiously constructed, £o as to admit of ready
absorption, and very tardy perspiration. Such
plants are accordingly designed to inhabit
hot sandy countries, where they are long

c

15 OF THE CUTICLE OR EPIDERMIS.

exposed to a burning sun, with very rare
supplies of rain.

This part allows also of the passage of air,
as is proved by experiments on the functions
of leaves. Light probably acts through it,
as the cuticle is a colourless membrane. We
know the effects of light to be very important
in the vegetable oeconomy.

But though this fine membrane admits
extraneous substances, so as to have their
due effect upon the vegetable constitution,
according to fixed laws, it no less powerfully
excludes all that would be injurious to the
plant, either in kind or proportion. Against
heat or cold it proves, in general, but a fee-
ble defence ; but when clothed with hair or
wool, it becomes a very powerful one. Against
the undue action of the atmosphere it is so
important a guard, that, when any tender
growing part is deprived of it, the greatest
mischiefs ensue. It forms in the Vegetable,
as well as the Animal, a fine but essential
barrier between life and destruction.

Some have imagined that the cuticle gave
form to the vegetable body, because it some-
times being over tight causes contractions on

OF THE CUTICLE OR EPIDERMIS. 19

the stem of a tree, as in the plum or cherry,
and because it is found to be cracked wherever
an unnatural excrescence is produced on the
bark. No doubt the cuticle is formed so as
to accommodate itself only to the natural
growth of the plant, not to any monstrosities,
and those lumps cause it to burst; just as it
happens to ripe fruits in very wet seasons.
Their cuticle is constructed suitably to their
usual size or plumpness, but not to any im-
moderate increase from too great absorption
of wet. If the cuticle be removed from any
part, no swelling follows, as it would if this
membrane only kept the tree in shape.

The extension of the cuticle is astonishing
if we consider that it is formed, as Grew well
observes, on the tenderest embryo, and only
extended during the growth of the plant, and
that it appears not to have any connexion
with the vascular or living part of the veoe-
table body, But though so accommodating
in those parts where it is wanted, on the old
trunks of most trees it cracks in every direc-
tion, and in many is entirely obliterated,
the old dead layers of their bark performing
all the requisite offices of a cuticle.

20 OF THE CUTICLE OTl EPIDERMIS,

M. Mirbel indeed, though he admits the
importance of this part in the several ways
above mentioned, contends that it is not a
distinct organ like the cuticle of animals*
but merely formed of the cellular parts of the
plant dilated and multiplied, and changed
by their new situation. This is very true;
but upon the same principle the human
cuticle can scarcely be called a distinct organ.
Its texture is continually scaling off exter-
nally, and it is supplied with new layers from
within. Just so does the cuticle of the Birch
peel off in scales, separable, almost without
end, into smaller ones.

Examples of different kinds of cuticle may
be seen in the following plants.

On the Currant tree it is smooth, and scales
off in large entire flakes, both from the young
branches and old stem. The same may be
observed in the Elder.

The fruit of the Peach and the leaf of the
Mullein have a cuticle covered with dense
and rather harsh wool, such as is found on
many Mexican plants, and on more Cretan
ones. The latter we know grow in open
places under a burning sun.

OP THE CUTICLE OR EPIDERMIS. 21

The leaf of the White Willow is clothed
with a. fine silky or satiny cuticle.

The cuticle of the Betony, and of many
other plants, is extended into rigid hairs or
bristles, which in the Nettle are perforated
and contain a venomous fluid.

On the fruit of the Plum, and on many
leaves, we find a blueish dry powder covering
the cuticle, which is a resinous exudation, and
it is difficult to wet the surface of these plants.
Rain trickles over them in large drops.

In the Cork tree, the Common Maple, and
even the Dutch Elm, the cuticle is covered
with a fungous substance most extraordinary
in its nature, though familiar to us as cork.

In grasses and some other plants the ingeni-
ous Mr. Davy has found a flintv substance in
the cuticle.

What seems to be the cuticle on the trunk
of the Plane, the Fir, and a kind of Wil-
low called Salix triandra, rather consists
of scales of bark, which having performed
their functions and become dead matter, are
rejected bj r the increasing bark beneath them;
and this accords with M. MirbeFs idea o£

23 OF THE CUTICLE OR EPIDERMIS,

the cuticle. The old layers of bark in the
Chesnut, Oak, and many other trees, though
not cast off, are of the same nature; and
these under the microscope exhibit the same
cellular texture as the real cuticle.

23

CHAPTER IV.

OF THE CELLULAR IXTEGUMEXT.

Immediately under the Cuticle we find a
succulent cellular substance , for the most
part of a green colour, at least in the leaves
and branches, which is called by Du Hamel
the Enveloppe cellulaire, and by Mirbel the
Tissu herbacL This is in general the seat
of colour, and in that respect analogous to
therete mucosum, or pulpy substance situated
under the human cuticle, which is red in the
European, and black in the Negro; but we
must carry the analogy no further, for these
two parts perform no functions in common.
Du Hamel supposed this pulp to form the
cuticle ; but this is improbable, as his expe-
riments show, when that membrane is re-
moved, that the Cellular Integument ex-
foliates, at least in trees, or is thrown off in
consequence of the injury it has sustained,

24 OF THE CELLULAR INTEGUMENT,

and a new cuticle, covering a new layer of
the same succulent matter, is formed under
the old one. Annual stems or branches have
not the same power, any more than leaves.

But little attention has been paid to this
organ till lately, though it is very universal,
even, as Mirbel observes, in Mosses and
Ferns. The same writer remarks that " leaves
i£ consist almost entirely of a plate of this
;i substance, covered on each side by the
^ cuticle. The stems and branches of both
" annual and perennial plants are invested
" with it ; but in woody parts it is dried up
" and •reproduced continually, such parts
" only having that reproductive power. The
4i old layers remain, are pushed outward
iC by the new ones, and form at length the
" rugged dry dead covering of .the old trunks
** of trees."

When we come to consider the curious
functions of leaves, we shall find this part
to be of the very first importance. In it
the principal changes operated upon the juices
of plants by light and air, and the conse-
quent elaboration of all their peculiar secrei
tions, take place.

Vb

CHAPTER V

OF THE BARK

U xder the Cellular Integument we find the
Bark, consisting of but one layer in plants or
branches only one year old, and often not
distinguishable from the wood. In the older
branches and trunks of trees, it consists of as
many layers as they are years old, the in-
nermost being called the liber ; and it is in
this layer only that the essential vital func-
tions are carried on for the time beino*.
after which it is pushed outwards with the
Cellular Integument, and becomes like that
a lifeless crust. These older layers, however,
are for some time reservoirs of the peculiar
secreted juices of the plant, which perhaps
they may help to perfect.

In some roots the bark, though only of
annual duration, is very thick; as in trie

26 OF THE BARK.

Carrot, the red part of which is all bark.
In the Parsnep, though not distinctly colour-
ed, it is no less evident. In the Turnip it is
much thinner, though equally distinct from
the wood or body of the root.

The Bark contains a great number of
woody fibres, running for the most part lon-
gitudinally, which give it tenacity, and in
which it differs very essentially from the parts
already described. These woody fibres when
separated by maceration exhibit in general
a kind of net-work, and in many instances
great regularity and beauty of structure. In
a family of plants to which the Mezereon be-
longs, the fibres of the inner bark have a
beautiful white shining appearance like silk.
In one of this tribe, a native of Jamaica, and
called Lace Bark, that part may be separated
by lateral extension into an elegant kind of
lace.

In the old bark of the Fir tribe, on the
contrary, nothing of this kind is discernible.
The bark of the Cluster Pine, Pinus Pinaster,
some inches in thickness, is separable into
thin porous layers, each of them the produc-
tion of one season, which do really seem te

OF THE BARK. 27

be, according to M. Mirbel's theory, hard-
ened and dried Cellular Integument; but
they are rather perhaps that vascular part of
the Bark which once contained the secreted
fluid, or turpentine, so abundant in this tree.

The bark of Oak trees twenty or thirty
years old, if cut and long exposed to the
weather, separates into many fine thin layers,
of a similar, though less delicate, texture
to the Lace Bark of Jamaica. All these
layers, in a living state, are closely connected
with each other by the cellular texture which
pervades the vegetable body in general, as
well as by transverse vessels necessary for the
performance of several functions hereafter to
be mentioned.

In the bark the peculiar virtues or qualities
of particular plants chiefly reside, and more
especially in several of its internal layers
nearest to the wood. Here we find in appro-
priate vessels the resin of the Fir and Juniper,
the astringent principle of the Oak and Wil-
low, on which their tanning property depends,
the fine and valuable bitter of the Peruvian
Bark, and the exquisitely aromatic oil of the
Cinnamon. The same secretions do indeed

OP THE BARK.

more or less, pervade the wood and other parts
of these plants, but usually in a less concen-
trated form.

When a portion of the bark of a tree is
removed, the remainder has a power of ex-
tending itself laterally, though very gradu-
ally, till the wound is closed. This is accom-
plished by each new layer, added to the
bark internally, spreading a little beyond the
edge of the preceding layer. The operation
of closing the wound goes on the more slowly,
as the wood underneath, from exposure
to the air, has become dead, and frequently
rotten, proving an incumbrance, which though
the living principle cannot in this instance free
itself from, it has no power of turning to any
good account. If, however, this dead wood
be carefully removed, and the wound pro-
tected from the injuries of the atmosphere,
the new bark is found to spread much more
rapidly; and as every new layer of bark forms,
as will be proved in the next chapter, a
new layer of wood, the whole cavity, what-
ever it may be, is in process of time iilled up.

This operation of Nature was turned to
gteat advantage by the late Mr, Forsyth of

OP THE BARK.

Kensington gardens, the history of whose ex-
periments is before the public. Under his
management many timber trees, become
entirely hollow, were filled with new wood,
and made to produce fresh and vigorous
branches ; and pear-trees planted in the time
of Kino; AVilliam, and become so decayed and
knotty as to bear no fruit worth gathering,
were by gradual paring away of the old wood
and bark, and the application of a composi-
tion judiciously contrived to stick close and
keep out air and wet, restored to such health
and strength as to cover the garden walls with
new branches bearing a profusion of fine fruit.
These experiments have passed under my
own actual observation, and I am happy to
bear testimony to the merits of a real lover of
useful science, and one of the most honest
and disinterested men I ever knew.

SO

CHAPTER VI.

OF THE WOOD.

When the bark is removed, we come to
the substance of the wood, which makes the
principal bulk of the trunk or branch of a
tree or shrub. When cut across, it is found
to consist of numerous concentric layers,
very distinct in the Fir, and other European
trees in general. Each of these circular
layers is externally most hard and solid.
They differ however among themselves in
this respect, as well as in their breadth on
the whole. It often happens that all the
layers are broadest towards one side of the
tree, so that their common centre is thrown
very much out of the actual centre of the
trunk.

The wood owes its strength and tenacity
to innumerable woody fibres, and consists
2

OF THE WOOD. 31

of various vessels running for the most part
longitudinally; some having a spiral coat,
others not. Of these vessels, some in their
youngest state convey the sap from the
root to the extremities of the branches and
leaves ; others contain the various peculiar
or secreted juices ; others perhaps contain
air. The whole are joined together by the
cellular substance already described.

Linnaeus and most writers believe that one
of the abovementioned circular layers of
wood is formed every year, the hard exter-
nal part being caused by the cold of winter ;
c onsequently, that the exact age of a sound
tree when felled may be known by counting
these rings. It has even been asserted that
the date of peculiarly severe winters may
be found in the harder more condensed rings
formed at those periods; and moreover, that
the north side of a tree may always be known
by the narrowness and density 6f the rings
on that side. All this is controverted by
Mirbel, chiefly on the authority of Du Hamel,
who nevertheless scarcely says enough to inva-
lidate the ancient opinion on the whole. It:
is very true that there may be occasional inter-

32 OP THE WOOD.

ruptions in the formation of the wood from cold
or fickle seasons, and that in some trees the
thin intermediate layers, hardly discernible
in general, which unite to form the principal
or annual ones, may, from such fluctuation
of seasons, become more distinct than ii
natural to them. Such intermediate layers
are even found more numerous in some
trees of the same speeies and age than in
others. But as there is always a most mate-
rial difference between summer and winter,
so I believe will there always be a clear di-
stinction between the annual rings of such
trees as show them at all. Trees of hot
countries indeed, as Mahogany, and ever-
greens in general, have them but indistinctly
marked; yet even in these they are to be
seen. With regard to their greater com-
pactness on the north side of a tree, Du
Hamel justly explodes this idea. In fact,
there is most wood formed, and consequently
these circles are broadest, on the side most
favourable to vegetation, and where there
are most branches and leaves. This in a
solitary tree is generally towards the south;
but it is easy to perceive the occasional varia-

OF THE WOOD. S3

tions which must arise from local exposure,
soil, moisture and other causes.

In some trees, a number of the outermost
rings differ greatly in colour from the inner-
most, and are called by workmen the sap.
In the Laburnum the former are yellow, the
latter brown. In the Oak and many other
trees a similar difference, though less striking,
'is perceptible, and in most the external rings
are much less firm, compact and durable
than the rest, retaining more vital principle,
and more of the peculiar juices of the plant.
Such rings are all comprehended by Du Hamel
under the name of Aubier, alburnum ; and
he rightly observes that this difference often
extends to a greater number of rings on one
side of a tree than on another. It seems
that the more vigour there is in a tree, or
side of a tree, the sooner is its alburnum
made perfect wood. By this term, however,
is properly understood only the layer of new
unhardened wood of the present year. When
the word alburnum is used in the following
pages, it applies to this part only.

Physiologists have long differed and do
still differ about the origin of the wood.

34 OF THE WOOD.

Malpighi and Grew thought it was formed
by the bark, and the best observations have
confirmed their opinion. Hales supposed the
wood added a new layer to itself externally
every year. Linnaeus had a peculiar notion,
that a new layer of wood was secreted annu-
ally from the pith, and added internally to
the former ones. Truth obliges us to confess
that the latter theory is most devoid of any
kind of proof or probability.

Du Hamel, by many experiments, proved
the wood to be secreted or deposited from
the innermost part of the bark or liber. He
introduced plates of tinfoil under the barks
of growing trees, carefully binding up their
wounds, and, after some years, on cutting
them across, he found the layers of new w r ood
on the outside of the tin. His original spe-
cimens I have examined in the public mu-
seum at Paris.

Dr. Hope, the late worthy Professor of
Botany at Edinburgh, instituted an experi-
ment, if possible more decisive, upon a branch
of Willow three or four years old. The bark
was carefully cut through longitudinally on
one side for the length of several inches, so

OP THE WOOD. 35

that it might be slipped aside from the wood
in the form of a hollow cylinder, the two
ends being undisturbed. The edges of the
bark were then united as carefully as possible,
the wood covered from the air, and the whole
bound up to secure it from external injury.
After a few years, the branch was cut through
transversely. The cylinder of bark was found
lined with layers of new wood, whose number
added to those in the wood from which it had
been stripped, made up the number of rings
in the branch above and below the experi-
ment. For an account of this experiment
I am indebted to Dr. Thomas Hope, the pre-
sent Chemical Professor at Edinburgh.

Du Hamel engrafted a portion of the bark
of a Peach-tree upon a Plum. After some
time he found a layer of new wood under
the engrafted bark, white like that of the
Peach, and evidently different from the
red wood of the Plum. Moreover, in this
and other experiments made with the same
intention, he found the layers of new wood
always connected with the bark, and not
united to the old wood. See his Physique
dcs Arbres, vol. 2. 29, &c. It deserves

d 2

35 OF THE WOOD,

also to be mentioned, that by performing this
experiment of engrafting a portion of bark at
different periods through the spring and sum-
mer, the same accurate observer found a
great difference in the thickness of the layer
of new wood produced under it, which was
always less in proportion as the operation
was performed later in the season.

That, the bark or liber produces wood
seems therefore proved beyond dispute, but
some experiments persuaded Du Hamel that
in certain circumstances the wood was capa-
ble of producing a new bark. This never
happened in any case but when the whole
trunk of a tree was stripped of its bark.
A Cherry-tree treated in this manner exuded
from the whole surface of its wood in little
points a gelatinous matter, which gradually
extended over the whole and became a new
bark, under which a layer of new wood was
speedily formed. Hence Mirbel concludes,
vol. 1. 176, that the alburnum and the
wood are really the origin of the new layers
of wood, by producing first this gelatinous
substance, or matter of organization, which
he and Du Hamel call cambium, and which

OF THE WOOD. 37

Mirbel supposes to produce the liber or
young bark, and at the same time, by a
peculiar arrangement of the vascular parts,
the alburnum or new wood. His opinion is
strengthened by the observation of a tribe
of plants to be explained hereafter, Palms,
Grasses, &c. in which there is no real bark,
and in which he finds that the woody fibres
do actually produce the cambium. Dr. Hope's
experiment will scarcely invalidate this opi-
nion, because it may be said the cambium
had already in that case formed the liber.

This matter will be better understood when
we come to speak of Mr. Knight's experiments
on the course of the sap.

38

CHAPTER VII.

OF THE MEDULLA OR PITH.

1 he centre or heart of the vegetable body,
within the wood, contains the Medulla or
Pith. This, in parts most endued with life,
as roots, and young growing stems or
branches, is a tolerably firm juicy substance,
of an uniform texture, and commonly a pale
green or yellowish colour. Such is its ap-
pearance in the young shoots of Elder in the
spring ; but in the very same branches, fully
grown, the pith becomes dry, snow-white,
highly cellular, and extremely light, capable
of being compressed to almost nothing. So
it appears likewise in the common Red or
White Currant, and numerous other plants.
In many annual stems the pith, abundant
and very juicy while they are growing, be-
comes little more than a web, lining the hol-
low of the complete stem, as in some This-

OF THE MEDULLA OR PITH. 39

ties. Many grasses and umbelliferous plants,
as Conium maculatum or Hemlock, have
always hollow stems, lined only with a thin
smooth coating of pith, exquisitely delicate
and brilliant in its appearance.

Concerning the nature and functions of
this part various opinions have been held.

Du Hamel considered it as merely cellular
substance, connected with what is diffused
through the whole plant, combining its vari-
ous parts, but not performing any remarkable
office in the vegetable oeconomy.

Linnaeus, on the contrary, thought it the
seat of life and source of vegetation ; that its
vigour was the main cause of the propulsion
of the branches, and that the seeds were
more especially formed from it. This latter
hypothesis is net better founded than his idea,
already mentioned, of the pith adding new
layers internally to the wood. In fact the
pith is soon obliterated in the trunks of many
trees, which nevertheless keep increasing,
for a long series of years, by layers of wood
added every year from the bark, even after
the heart of the tree is become hollow from
decay.

40 OF THE MEDULLA OR PITH.

Some considerations have led me to hold
a medium opinion between these two ex-
tremes. There is, in certain respects, an
analogy between the medulla of plants and
the nervous system of animals. It is no less
assiduously protected than the spinal marrow
or principal nerve. It is branched off and
diffused through the plant, as nerves are
through the animal. Hence it is not absurd
to presume that it may, in like manner,
give life and vigour to the whole, though by
no means, any more than nerves, the organ
or source of nourishment. It is certainly
most vigorous and abundant in young and
growing branches, and must be supposed to
be subservient, in some way or other, to their
increase. Mr. Lindsay of Jamaica, in a pa-
per read long ago to the Royal Society, but
not published, thought he demonstrated the
medulla in the leaf-stalk of the Mimosa
pudica, or Sensitive Plant, to be the seat of
irritability, nor can I see any thing to invali-
date this opinion.

Mr. Knight, in the Philosophical Transac-
tions for 1801, p. 348, supposes the medulla
may be a reservoir of moisture, to supply

OF THE MEDULLA OR PITH, 41

the leaves whenever an excess of perspiration
renders such assistance necessary, and he
has actually traced a direct communication
by vessels between it and the leaf. a Plants,"
says that ingenious writer, " seem to require
some such reservoir; for their young leai 3
are excessively tender, and they perspire
much, and cannot, like animals, fly to the
shade and the brook/'

This idea of Mr. Knight's may derive con-
siderable support from the consideration of
bulbous-rooted grasses. The Common Cats-
tail, Phleum pratense, Engl. Bot. t. 1076,
when growing in pastures that are uniformly
moist, has a fibrous root, but in dry situa-
tions, or such as are only occasionally wet y
it acquires a bulbous one, whose inner sub-
stance is moist and fleshy, like the pith of
young branches of trees. This is evidently
a provision of Nature to guard the plant
against too sudden a privation of moisture
from the soil.

But, on the other hand, all the moisture
in the medulla of a whole branch is, in some
cases, too little to supply one hour's perspi-
ration of a single leaf. Neither can I find

42 OF .THE MEDULLA OR PITH.

that the moisture of the medulla varies, let
the leaves be ever so flaccid. I cannot but
incline therefore to the opinion that the
medulla is rather a reservoir of vital energy,
even in these bulbous grasses.

Mr. Knight has shewn that the part in
question may be removed without any great
injury to a branch, or at least without im-
mediate injury, but I have had no oppor-
tunity of making any experiments on this
particular subject.

43

CHAPTER VIII.

OF THE SAP-VESSELS, AND COURSE OF
THE SAP; WITH MR. KNIGHT^ THEORY
OF VEGETATION.

Much contrariety of opinion has existed
among physiologists concerning the vascular
system of plants, and the nature of the pro-
pulsion of the sap through their stems and
branches. Indeed it is a subject upon which,
till lately, very erroneous ideas have pre-
vailed.

That the whole vegetable body is an as-
semblage of tubes and vessels is evident to
the most careless observer; and those who are
conversant with the microscope, and books
relating to it, have frequent opportunities of
observing how curiously these vessels are ar-
ranged, and how different species of plants.

44 OF THE SAP-VESSELS.

especially trees, differ from each other in the
structure and disposition of them. Such ob-
servations, however, if pursued no further,
lead but a little way towards a knowledge of
the wonderful physiology of vegetables.

In our 2d chapter, mention is made of the
general cellular and vascular texture of plants ;
we must now be a little more particular in our
inquiries.

That plants contain various substances, as
sugar, gum, acids, odoriferous fluids and
others, to which their various flavours and
qualities are owing, is familiar to every one ;
and a little reflection will satisfy us that such
substances must each be lodged in proper
Cells and vessels to be kept distinct from each
other. They are extracted, or secreted, from
the common juice of the plant, and called its
peculiar or secreted fluids. Various experi-
ments and observations, to be hereafter en-
larged upon, prove also that air exists in the
vegetable body, and must likewise "be con-
tained in appropriate vessels. Besides these*
we know that plants are nourished and invi-
gorated by water, which they readily absorb,
and which is quickly conveyed through their

OF THE SAP-VESSELS. 45

stalks and leaves, no doubt by tubes or ves-
sels on purpose. Finally, it is observable that
all plants, as far as any experiment has been
made, contain a common fluid, which at cer-
tain seasons of the year is to be obtained in
great quantity, as from vine branches by
wounding them in the spring before the leaves
appear, and this is properly called the .sap.
It is really the blood of the plant, by which
its whole body is nourished, and from which
the peculiar secretions are made.

The great difficulty has been to ascertain
the vessels in which the sap runs. Two of
the most distinguished inquirers into the sub-
ject, Malpighi and Grew, believed the woody
fibres, which make so large a part of the ve-
getable body, and give it consistence and
strength, to be the sap-vessels, analogous to
the blood-vessels of animals, and their opi-
nion was adopted by Du Hamel. In support
of this theory it was justly observed that these
fibres are very numerous and strong, running
longitudinally, often situated with great uni-
formity jUh argument for their great import-
ance), and found in all parts of a plant, al-
though in some they are so delicate as to be

46 OP THE SAP-VESSELS.

scarcely discernible. But philosophers sought
in vain for any perforation, any thing like a
tubular structure, in the woody fibres to
countenance this hypothesis, for they are di-
visible almost without end, like the muscular
fibre. This difficulty was overlooked, because
of the necessity of believing the existence of
sap-vessels somewhere ; for it is evident that
the nutrimental fluids of a plant must be car-
ried with force towards certain parts and in
certain directions, and that this can be accom-
plished by regular vessels only, not, asTourne-
fort supposed, by capillary attraction through
a simple spongy or cottony substance.

I received the first hint of what I now be-
lieve to be the true sap-vessels from the 2d
section of Dr. Darwin's Phytologia, where it
is suggested that what have been taken for
air-vessels are really absorbents destined to
nourish the plant, or, in other words, sap-
vessels. The same idea has been adopted, con-
firmed by experiments, and carried to much
greater perfection by Mr. Knight, whose pa-
pers in the Philosophical Transactions for
1801, 1804 and 1805 throw the most brilliant
light upon it, and, I think, establish no less

OF THE SAP-VESSELS. 47

than an entirely new theory of vegetation, by
which the real use and functions of the prin-
cipal organs of plants are now for the first
time satisfactorily explained.

In a young branch of a tree or shrub, or in
the stem of an herbaceous plant, are found,
ranged round the centre or pith, a number of
longitudinal tubes or vessels, of a much more
firm texture than the adjacent parts, and when
examined minutely, these vessels often appear
to be constructed with a spiral coat. This may
be seen in the young twigs and leaf-stalks of
Elder, Syringa, and many other shrubs, as well
as in numerous herbaceous plants, as the Peo-
ny, and more especially many of the Lily tribe.
If a branch or stalk of any of these plants be
partly cut through or gently broken, and its
divided portions slowly drawn asunder, the
spiral coats of their vessels will unroll, exhi-
biting a curious spectacle even to the naked
eye. In other cases, though the spiral struc-
ture exists, its convolutions are scarcely se-
parable at all, or so indeterminate as to be
only marked by an interrupted line of perfo-
rations or slits, as shown by M. Mirbel.
Indeed the very same brandies which exhibit

48 OF THE SAP-VESSELS

these spiral vessels when young, show no signs
of them at a more advanced period of growth,
when their parts are become more woody,
firm and rigid. No such spiral-coated vessels
hare been detected in the bark at any period
of its growth.

Malpighi asserts that these vessels are al-
ways found to contain air only, no other fluid;
while Grew reports that he sometimes met
with a quantity of moisture in them. Both
judged them to be air-vessels, or, as it were,
the lungs of plants, communicating, as these
philosophers presumed, with certain vessels of
the leaves and flowers, of an oval or globular
form, but destitute of a spiral coat. These
latter do really contain air, but it rather ap-
pears from experiment that they have no di-
rect communication with the former. Thus
the tubes in question have always been called
air-vessels, till Darwin suggested their real
nature and use *, He is perhaps too decisive
when he asserts that none of them are air-
vessels because they exist in the root, which is

* Du Hamel, indeed, once suspected that they con-
tained " highly rarefied sap," but did not pursue the
jaea.

dr. darwin's experiments. 49

not exposed to the atmosphere. We know
that air acts upon the plant under ground,
because seeds will not vegetate in earth un-
der the exhausted receiver of an air-pump.
Phil. Trans. No. 25. I do not however
mean to contend that any of these spiral ves-
sels are air-vessels, nor do I see reason to
believe that plants have any system of longi-
tudinal air-vessels at all, though they must
be presumed to abound in such as are trans-
verse or horizontal.

Dr. Darwin and Mr. Knight have, by the
most simple and satisfactory experiment,
proved these spiral vessels to be the channel
through which the sap is conveyed. The
former placed leafy twigs of a common Fig-tree
about an inch deep in a decoction of madder,
and others in one of logwood. After some
hours, on cutting the branches across, the
coloured liquors were found to have ascended
into each branch by these vessels, which ex-
hibited a circle of red dots round the pith,
surrounded by an external circle of vessels
containing the white milky juice, or secreted
fluid, so remarkable in the fig-tree. Mr.
Knight, in a similar manner, inserted the

E

50 MR. KNIGHTS EXPERIMENTS.

lower ends of some cuttings of the Apple-tre<f
and Horse-chesnut into an infusion of the skins
of a very black grape in water, an excellent
liquor for the purpose. The result was simi-
lar. But Mr. Knight pursued his observations
much further than Dr. Darwin had done ; for
he traced the coloured liquid even into the
leaves, " but it had neither coloured the bark
nor the sap between it and the wood ; and the
medulla was jnrot affected, or at most was very
slightly tinged at its edges." Phil. Trans,
for 1801, p. 335.

The result of all Mr. Knight's experiments
and remarks seems to be, that the fluids des-
tined to nourish a plant, being absorbed by
the root and become sap, are carried up into
the leaves by these vessels, called by him cen-
tral vessels, from their situation near the pith.
A particular set of them, appropriated to each
leaf, branches off, a few inches below the leaf
to which they belong, from the main channels
that pass along the alburnum, and extend
from the fibres of the root to the extremity
of each annual shoot of the plant. As they
approach the leaf to which they are destined,
the central vessels become more numerous,

PROPULSION OF THE SAP. 51

or subdivided. " To these vessels/' says Mr.
Knight, " the spiral tubes are every where
appendages." p. 536. By this expression,
and by a passage in the following page*, 337,
this writer might seem to consider the spiral
line, which forms the coats of these vessels,
as itself a pervious tube, or else that he was
speaking of other tubes with a spiral coat,
companions of the sap-ve3sels ; but the plate
which accompanies his dissertation, and the
perspicuous mode in which he treats the sub-
ject throughout, prevent our mistaking him
on the last point. In order to conceive how
the sap can be so powerfully conveyed as it
is through the vessels in which it flows, from
the root of a tall tree to its highest branches,
we must take into consideration the action of
heat. We all know that this is necessary to
the growth and health of plants ; and that it
requires to be nicely adjusted in degree, in

* te The whole of the fluid, which passes from the wood
to the leaf, seems to me evidently to be conveyed through
a single kind of vessel ; for the spiral tubes will neither
carry coloured infusions, nor in the smallest degree re-
tard the withering of the leaf, when the central vessels
are divided.' Knight.

e2

Si PROPULSION OF THE SAP.

prcler to suit the constitutions of different
tribes of plants destined for different parts of
the globe. It cannot but act as a stimulus
to the living principle, and is one of the most
powerful agents of Nature upon the vegetable
as well as animal constitution. Besides this,
however, various mechanical causes may be
supposed to have their effect ; as the frequently
spiral or screw-like form of the vessels, in
some of which, when separated from the plant,
Malpighi tells us he once saw a very beauti-
ful undulating motion that appeared sponta-
neous. This indeed has not been seen by any
other person, nor can it be supposed that
parts so delicate can, in general, be removed
from their natural situation, without the de-
struction of that fine irritability on which such
a motion must depend. We may also take
into consideration the agitation of the vege-
table body by winds, which is known by ex-
perience to be so wholesome to it*, and must
serve powerfully to propel the fluids of lofty
trees; the passage, and evolution perhaps, of

* See Mr. Knight's experiments in confirmation of this
in the Phil. Trans, for 1803, p. 280.

ACTION OP THE SILVER GRAIN. 53

air in other parts or vessels, surrounding and
compressing these ; and lastly the action, so
ingeniously supposed by Mr. Knight, of those
thin shining plates called the silver grain,
visible in oak wood, which pressing upon the
sap-vessels, and being apparently susceptible
of quick changes from variations in heat or
other causes, may have a powerful effect.
" Their restless temper/' says Mr. Knight,
" after the tree has ceased to live, inclines
me to believe that they are not made to be
idle whilst it continues alive/' PhiL Trans,
for 1801, p. 344. These plates are presumed
by the author just quoted to be peculiarly
useful in assisting the ascent of the sap
through the alburnum of the trunk or chief
branches, where indeed the spiral coats of
the vessels are either wanting, or less elastic
than in the leaf-stalks and summits of the
more tender shoots.

However its conveyance may be accom-
plished, it is certain that the sap does reach
the parts above mentioned, and there can
surely be now as little doubt of the vessels
in which it runs. That these vessels have
been thought to contain air only, is well ac-

54 COURSE OF THE SAP.

counted for by Dr. Darwin, on the principle
of their not collapsing when emptied of their
•sap ; which is owing to their rigidity, and the
elastic nature of their coats. When a portion
of a stem or branch is cut off, the sap soon
exhales from it, or rather is pushed out by the
action of the vessels themselves : hence they
are found empty ; and for the same reason
the arteries of animals were formerly thought
to contain air only. When the sap-vessels
have parted with their natural contents, air
and even quicksilver will readily pags through
them, as is shown by various experiments.
Arguments in support of any theory must be
very cautiously deduced from such expert
ments, or from any other observations not
made on vegetables in their most natural state
and condition; and, above ail, that great
agent the vital principle must always bp kept
in view, in preference to mere mechanical con-
siderations.

These to which I give the common name
of sap-vessels, comprehending the common
tubes of the alburnum, and the central ves-
sels, of Mr. Knight, may be considered as
analogous to the arteries of animals ; or rather

COURSE OF THE SAP.. 5$

they are the stomach, laeteajs and arteries all
in one, for I conceive it to be a great error in
Dr. Darwin to call by this name the vessels
which contain the peculiar secretions of the
plant*. These sap-vessels, no doubt, absorb
the nutritious fluids afforded by the soil, in
winery possibly, as they pass through the root,
some change analogous to digestion may take
place ; for there is evidently a great difference,
in many cases, between the fluids of the root,
at least the secreted ones, and those of the rest
of the plant; and this leads us to presume that
some considerable alteration may be wrought
in the sap in its course through that impor-
tant organ. The stem, which it next enters,
is by no means an essential part, for we see
many plants whose leaves and flowers grow
directly from the root.

Part of the sap is conveyed into the flowers
and fruit, where various fine and essential se r
cretions are made from it, of which we shall
speak hereafter. By far the greater portion
of the sap is carried into the leaves, of the
great importance and utility of which to the
pjant itself Mr. Knight's theory is the only one

* PInjtologia, sect. 2,

56* COURSE OF THE SAP.

that gives us any adequate or satisfactory no-
tion. In those organs the sap is exposed to
the action of light, air and moisture, three
powerful agents, by which it is enabled to
form various secretions, at the same time that
much superfluous matter passes off by per-
spiration. These secretions not only give pe-
culiar flavours and qualities to the leaf itself,
but are returned by another set of vessels, as
Mr. Knight has demonstrated, into the new
layer of bark, which they nourish and bring
to perfection, and which they enable in its
turn to secrete matter for a new layer of al-
burnum the ensuing year. It is presumed
that one set of the returning vessels of trees
may probably be more particularly destined
to this latter office, and another to the secre-
tion of peculiar fluids in the bark. See Phil,
Trans, for 1801, p. 337- In the bark princi-
pally, if I mistake not, the peculiar secretions
of the plant are perfected, as gum, resin, &c,
each undoubtedly in an appropriate set of
vessels. From what has just been said of the
office of leaves, we readily perceive why all
the part of a branch above a leaf or leaf-bud
dies when cut, as each portion receives nou-

GROWTH OF MONOCOTYLEDONES. 5?

rishment, and the means of increase, from
the leaf above it.

By the above view of the vegetable cecono-
my, it appears that the vascular system of
plants is strictly annual. This, of course, is
admitted in herbaceous plants, the existence
or whose stems, and often of the whole in-
dividual, is limited to one season ; but it is
no less true with regard to trees. The layer
of alburnum on the one hand is added to the
wood, and the liber, or inner layer of the
bark, is on the other annexed to the layers
formed in preceding seasons, and neither have
any share in the process of vegetation for the
year ensuing. Still, as they continue for a
long time to be living bodies, and help to
perfect, if not to form, secretions, they must
receive some portion of nourishment from
those more active parts which have taken up
their late functions.

There is a tribe of plants called monocoty-
ledoncs, characterized by having only one
lobe to the seed, whose growth requires par-
ticular mention. To these belongs the natural
order of Palms, which being the most lofty,
and, in some instances, the most long-lived

55 GROWTH OF MOKO.COTYLEDCNES.

of plants, have justly acquired the name of
trees. Yet, paradoxical as it may seem, they
are rather perennial herbaceous plants, having
nothing in common with the growth of trees
in general. Their nature has been learnedly
explained by M. Desfontaines, a celebrated
French botanist, and by M. Mirbel in his
Traitt d'Anatomie etdePhy&Qlogie Vegetales,
vol. 1. p. 209, and Linnaeus has long ago made
remarks to the same purpose. The Palms are
formed of successive circular crowns of leaves*
which spring directly from the root. These
leaves and their footstalks are furnished with
bundles of large sap-vessels and returning ves-
sels, like the leaves of our trees. When
one circle of them has performed its office,
another is formed within it, which being con-
fined below, necessarily rises a little above
the former. Thus successive circles grow one
above the other, by which the vertical in-
crease of the plant is almost without end.
Each circle of leaves is independent of its pre-
decessor, and has its own clusters of vessels,
so that there can be no aggregation of woody
circles; and yet in some of this tribe the,
spurious kind of stem, formed in the manner

OT REVERSED PLANTS. 50

just described, when cut across shows some-
thing of a circular arrangement of fibres,
arising from the original disposition of the
leaves. The common orange lily, Lilium hul*
biferum, Curt. Mag, t. 36, and white lily,
L.candidum, f.278, which belong to the same
natural family of monocotyledones, serve to
elucidate this subject. Their stems, though
of only annual duration, are formed nearly
gn the same principle as that of a Palm, and
are really congeries of leaves rising; one above
another, and united by their bases into an
apparent .stem. In these the spiral coats of
the sap-vessels are very easily discernible.

To conclude this subject of the propulsion
of the sap, it is necessary to say a few words
on the power which the vessels of plants are
reported to possess of conveying their appro-
priate fluids equally well in either direction ;
or, in other words, that it is indifferent" whe-
ther a cutting of any kind be planted with its
upper or lower end in the ground. On this
subject also Mr. Knight has afforded us new
information, by observing that, in cuttings so
treated, the returning vessels retain so much
of their original nature as to deposit new wood

60 OF REVERSED PLANTS.

above the leaf-buds; that is, in the part of the
cutting which, if planted in its natural posi-
tion, would have been below them. It ap-
pears, however, that the sap-vessels must ab-
sorb and transmit their sap in a direction con-
trary to what is natural ; and it is highly pro-
bable, that after some revolving seasons new
returning vessels would be formed in that part
of the stem which is now below the buds. I
presume there can be no doubt that successive
new branches would deposit their wood in the
usual position. It is nevertheless by no means
common for such inverted cuttings to succeed
at all. An experiment to a similar purpose is
recorded by Dr. Hales, Vegetable Staticks,
p. 132, t. 1 1, of engrafting together three trees
standing in a row, and then cutting off the
communication between the central one and
the earth, so that it became suspended in the
-dir, and was nourished merely through its late-
ral branches. The same experiment was success-
fully practised by the late Dr. Hope at Edin-
burgh upon three Willows, and in the years
1781, 2, and 3, I repeatedly witnessed their
health and vigour. It was observed that the
central tree was several days later incoming

OF REVERSED PLANTS. Gl

into leaf than its supporters, but I know not
that any other difference was to be perceived
between them. The tree which wanted the
support of the ground was, some years after,
blown down, so that we have now no oppor-
tunity of examining the course of its vessels,
or the mode in which successive layers of
wood were deposited in its branches ; but the
experiment is easily repeated.

In the weeping variety of the Common Ash.
now so frequent in gardens, the branches are
completely inverted as to position, } r et the
returning fluids appear to run exactly in their
natural direction, depositing new wood, as
they are situated above the buds or leaves ;
and if the end of any branch be cut, all be-
yond (or below) the next bud dies ; so that in
this case gravitation, to which Mr. Knight
attributes considerable pow r er over the return-
ing fluids, Phil Trans, for 1804, does not
counteract the ordinary course of nature.

CHAPTER IX.

OF THE SAP, AND INSENSIBLE PERSPl
RATION.

1 he sap of trees, as has been' mentioned in
the last chapter, may be obtained by wound*
ing a stem or branch in spring, just before
the buds open, or in the end of autumn,
though less copiously, after a slight frost ;
yet not during the frost. In the Palm-trees
of hot countries, it is said to flow from a
wound at any time of the year. It has al-
ways been observed to flow from the young
wood or alburnum of our trees, not from
the bark; which agrees with Mr. Knight's
theory.

A common branch of the Vine cut through
will yield about a pint of this fluid in the course
of twenty-four hours. The Birch, Betula
alba, affords plenty of sap; some other trees
yield but a small quantity. It flows equally

OF THE SAP, AND INSENSIBLE PERSPIKATiaN. 63

upward and downward from a wound, at least
proportionably to the quantity of stem or
branch in either direction to supply it. Some
authors have asserted that in the heat of the
day it flows most from the lower part of a
wound, and in the cool of the evening from
the upper : hence they concluded it was
ascending during the first period, and de-*
scending in the latter. If the fact be true,
some other solution must be sought ; nor
would it be difficult to invent a theory upon
this subject : but we rather prefer the investi*
gation of truth on more solid foundations.

This great motion, called tYieflozcing, of
the sap, which is to be detected principally in
the spring, and slightly in the autumn, is
therefore totally distinct from that constant
propulsion of it going on in every growing
plant, about which so much has been said in
the preceding chapter, and which is proved
by taking an entire herb of any kind that has
been gathered and suffered to begin to fade,
and immersing its root in water. By absorp-
tion through the sap-vessels it presently re-
vives, for those vessels require a const/jnt sup -
ply from the root.

64 OP THE SAP, AND INSENSIBLE PERSPIRATION.

This flowing of the sap has been thought
to demonstrate a circulation, because, there
being no leaves to carry it off by perspiration,
it is evident that, if it were at these periods
running up the sap-vessels with such velocity,
it must run down again by other channels.
As soon as the leaves expand, its motion is
no longer to be detected. The effusion of
sap from plants, when cut or wounded, is,
during the greater part of the year, compa-
ratively very small. Their secreted fluids run
much more abundantly.

I conceive therefore that this flowing is no-
thing more than a facility in the sap to run,
owing to the peculiar irritability of the ve-
getable body at the times above mentioned;
and that it runs only when a wound is made,
being naturally at rest till the leaves open,
and admit of its proper and regular convey-
ance. Accordingly, ligatures made at this
period, which show so plainly the course of
the blood in an animal body, have never
been found to throw any light upon the vege-
table circulation. This great facility in the
sap to run is the first step towards the revi-
val of vegetation from the torpor of winter ;

OF THE SAP, AND INSENSIBLE PERSPIRATION. 65

and its exciting cause is heat, most unques-
tionably by the action of the latter on the
vital principle, and scarcely by any mechani-
cal operation, or expansive power upon the
fluids. The effect of heat is in proportion to
the degree of cold to which the plant has been
accustomed. In forced plants the irritabi-
lity, or, to use the words of a late ingenious
author*, who has applied this principle very
happily to the elucidation of the animal eco-
nomy, excitability ', is exhausted, as Mr. Knight
well remarks, and they require a stronger sti-
mulus to grow with vigour. See. p. 91. Hence
vegetation goes on better in the increasing
heat of spring than in the decreasing heat of
autumn. And here I cannot but offer, by
way of illustration, a remark on the theory
advanced by La Cepede, the able continua-
tor of Buffon, relative to serpents. That in-
genious writer mentions, very truly, that
these reptiles awake from their torpid state in
the spring, while a much less degree of heat
exists in the atmosphere than is perceptible

* Dr. John Brown, formerly of Edinburgh. See the
14th Section of Dr. Darwin's Phytologia on this sub-
ject.

F

65 OF THE SAP,

*

in the autumn, when, seemingly from the in-
creasing cold, they become benumbed ; and
he explains it by supposing a greater degree
of electricity in the air at the former season.
Dr. Brown s hypothesis, of their irritability
being as it were accumulated during winter,
offers a much better solution, either with re-
spect to the animal or vegetable constitution.
For the same reason, it is necessary to apply
warmth very slowly and carefully to persons
frozen, or even chilled only, by a more than
usual degree of cold, which renders them
more susceptible of heat, and a temperate
diet and very moderate stimulants are most
safe and useful to the unexhausted constitu-
tions of children. The same principle ac-
counts for the occasional flowing of the sap in
autumn after a slight frost. Such a prema-
ture cold increases the sensibility of the plant
to any warmth that may follow, and produces,
in a degree, the same state of its constitution
as exists after the longer and severer cold of
winter. Let me be allowed a further illustra-
tion from the animal kingdom. Every body
conversant with labouring cattle must have
observed how much sooner they are exhaust-

8

AND INSENSIBLE PERSPIRATION, 67

ed by the warm days- of autumn, when the
nights are cold, than in mueh hotter weather
in summer, and this is surely from the same
cause as the autumnal flowing of the vegetable
sap.

The sap, or lymph, of most plants when
collected in the spring as abovementioned,
appears to the sight and taste little else than
water, but it soon undergoes fermentation
and putrefaction. Even that of the vine is
scarcely acid, though it can hardly be ob-
tained without some of the secreted juices,
which in that plant are extremely acid and
astringent. The sap of the sugar maple,
Acer saccharinum, has no taste, though ac-
cording to Du Hamel every 200lb. of it will
afford 101b. of sugar. Probably, as he re-
marks, it is not collected without an admix-
ture of secreted fluids.

As soon as the leaves expand, insensible
perspiration takes place very copiously, chief-
ly from those organs, but also in some degree
from the bark of the young stem or branches.
The liquor perspired becomes sensible to us
by being collected from a branch introduced
into any sufficiently capacious glass vessel,

F2

68 OF THE SAP, AND INSENSIBLE PERSPIRATION.

and proves, for the most part, a clear watery
liquor like the sap, and subject to similar
chemical changes. It is observed to be uni-
form in all plants, or nearly so, as well as the
sap, except where odorous secretions transude
along with it. Still there must be a very es-
sential difference between the original sap of
any plant and its perspiration, the latter no
longer retaining the rudiments of those fine
secretions which are elaborated from the for-
mer; but that difference eludes our senses as
well as our chemistry. The perspiration of
some plants is prodigiously great. The large
Annual Sunflower, Helianthus annum, Ger-
arde TLmac. 751. f. 1, according to Dr. Hales,
perspires about 17 times as fast as the ordi-
nary insensible perspiration of the human skim
But of all plants upon record I think the Cor-
nelian Cherry, Cornus mascula, FL Grcec.
t. 151, is most excessive in this respect.
The quantity of fluid which evaporates from
its leaves in the course of 24 hours, is said to
be nearly equal to twice the weight of the
whole shrub. Du Hamel Phys. des Arbres,
*. 1. 145.

69

CHAPTER X,

OF THE SECRETED FLUIDS OF PLANTS
GRAFTING. HEAT OF THE VEGETABLE
BODY.

The sap in its passage through the leaves
and bark becomes quite a new fluid, possess-
ing the peculiar flavour and qualities of the
plant, and not only yielding woody matter
for the increase of the vegetable body, but
furnishing: various secreted substances, more
or less numerous and different among them-
selves. These accordingly are chiefly found
in the bark ; and the vessels containing them
often prove upon dissection very large and
conspicuous, as the turpentine-cells of the
Fir tribe. In herbaceous plants, whose stems
are only of annual duration, the perennial
roots frequently contain these fluids in tfye
most perfect state, nor are they, in such,

70 SECRETED FLUTDS.

confined to the bark, but deposited -through*
out the substance or wood of the root, as in
Rhubarb, Rheum pdlmatum, Linn.jiL Fasci
t. 4, and Gentian, Gentiana lutea and pur-
purea, Ger. emac. 432,/. 1,2. In the wood
of the Fir indeed copious depositions of tur-
pentine are made, and in that of every tree
more or less of a gummy, resinous or sac-
charine matter is found. Such must be
formed by branches of those returning ves-
sels that deposit the new alburnum. These
juices appear to be matured, or brought to
greater perfection, in layers of wood or bark
that have no longer any principal share in the
circulation of the sap.

The most distinct secretions of vegetables
require to be enumerated under several dif-
ferent heads.

Gum or mucilage, a viscid substance of
little flavour or smell, soluble in water, is
very general. When superabundant it ex-
udes from many trees in the form of large
drops or lumps, as in Plum, Cherry, and
Peach-trees, and different species of Mimosa
or Sensitive plants, one of which yields the
Gum Arabic, others the Gum Senegal, &c.

RESINOUS SECRETIONS. 71

Resin is a substance soluble in spirits, and
much more various in different plants than
the preceding, as the Turpentine of the Fir
and Juniper, the Red Gum of New South
Wales, produced by one or more species of
Eucalyptus, Bot. of N. Holl t. 13, and the
fragrant Yellow Gum of the same country,
see White s Voyage, 235, which exudes spon-
taneously from the Xanthorrlwa Hast He,
Most vegetable exudations partake of a na-
ture between these two, being partly soluble
in water, partly in spirits, and are therefore
called Gum-resins. The milky juice of the
Fig, Spurge, &c, which Dr. Darwin has
shown, and which every body may see, to be
quite distinct from the sap, is, like animal
milk, an emulsion, or combination of a wa-
tery fluid with oil or resin. Accordingly,
when suffered to evaporate in the air, such
fluids become resins or gum-resins, as the Gum
Euphorbium. In the Celandine, Chelidoni*
um majus, Engl. Bot. t. 1581, and some
plants allied to it, the emulsion is orange^-co*
Joured.

The more refined and volatile secretions of
a resinous nature are called Essential Oils,

72 BITTER SECRETION.

and are often highly aromatic and odoriferous.
One of the most exquisite of these is afforded
by the Cinnamon hark. They exist in the
highest perfection in the perfumed effluvia of
flowers, some of which, capable of combi-
nation with spirituous fluids, are obtainable
by distillation, as that of the Lavender and
Rose ; while the essential oil of the Jasmine
is best procured by immersing the flowers in
expressed oil which imbibes and retains their
fragrance. Such Expressed or Gross Oils, as
they are called, to distinguish them from es-
sential oils obtained by distillation, are chiefly
found in the seeds of plants. In the pulp of
the Olive indeed they occur in the form of
an emulsion, mixed with watery and bitter
fluids, from which the oil easily separates by
its superior lightness. These expressed oils
are not soluble in spirits or water, though by
certain intermediate substances they may be
rendered capable of uniting with both.

The Bitter secretion of many plants does
not seem exactly to accord with any of the
foregoing. Some facts would seem to prove
it of a resinous nature, but it is often per-
fectly soluble in water. Remarkable instances

ACID AND ALKALINE SECRETIONS. 73

of this secretion are in the Cinchona offi-
cinalis or Peruvian bark, Lambert Cinchona,
t. 1, and every species, more or less, of
Gentian.

-Acid secretions are well known to be very
general in plants. Formerly one uniform vege-
table or acetous acid was supposed common
to all plants, but the refinements of modern
chemistry have detected in some a peculiar
kind, as the Oxalic acid, obtained from Oxalis
or Wood Sorrel, and several others. The
astringent principle should seem to be a sort of
acid, of which there are many different forms
or kinds, and among them the tanning prin-
ciple of the Oak, Willow, &c.

On the other hand, two kinds of Alkali
are furnished by vegetables, of which the
most general is the Vegetable Alkali, pro-
perly so called, known by the name of Salt
of Tartar, or Salt of Wormwood, or more cor-
rectly by the Arabic term Kali. The Fossil
Alkali, or Soda, is most remarkable in cer-
tain succulent plants that grow near the sea,
belonging to the genera Chenopodiinn, Sal-
sola, &c. When these plants are cultivated
in a common soil, they secrete Soda as copi-.

74 SlfGAK.

ously, provided their health be good, as in
their natural maritime places of growth.

Sugar, more or less pure, is very generally
found in plants. It is not only the seasoning
of most eatable fruits, but abounds in various
roots, as the Carrot, Beet and Parsnip, and
in many plants of the grass or cane kind be-
sides the famous Sugar Cane, Saccharum offi-
cinarum. There is great reason to suppose
Sugar not so properly an original secretion, as
the result of a chemical change in secretions
already formed, either of an acid or mucila-
ginous nature, or possibly a mixture of both.
In ripening fruits this change is most striking,
and takes place very speedily, seeming to be
greatly promoted by heat and light. By the
action of frost, as Dr. Darwin observes, a dif-
ferent change is wrought in the mucilage of
the vegetable body, and it becomes starch.

A fine red liquor is afforded by some plants,
as the Bloody Dock or Rnmetf sanguineus*
Engl Bot. t . 1533, the Red Cabbage and Red
Beet, which appears only to mark a variety in
all these plants, and not to constitute a spe-*
cific difference. It is however perpetuated by
seed.

VARIETIES OF SECRETIONS. 7*

It is curious to observe, not only the vari-
ous secretions of different plants, or families
of plants, by which they differ from each
other in taste, smell, qualities and medical
virtues, but also their great number, and
striking difference, frequently in the same
plant. Of this the Peach-tree offers a familiar
example. The gum of this tree is mild and
mucilaginous. The bark, leaves and flowers
abound with a bitter secretion of a purgative
and rather dangerous quality, than which no-
thing can be more distinct from the gum.
The fruit is replete, not only with acid, mu-
cilage and sugar, but with its own peculiar
aromatic and highly volatile secretion,, elabo-
rated within itself, on which its fine flavour
depends. How faT are we still from under-
standing the whole anatomy of the vegetable
body, which can create and keep separate such
distinct and discordant substances !

Nothing is more astonishing than the se-
cretion of flinty earth by plants, which though
never suspected till within a few years, appears
to me well ascertained. A substance is found
in the hollow stem of the Bamboo, (Arundo
Ba?nbos of Linnaeus, Nastos of Theophrastus),

76 FLINTY SECRETION.

called Tabaxir or Tabasheer, which is suppo-
sed in the East Indies (probably because it is
rare and difficult of acquisition, like the ima-
ginary stone in the head of a toad) to be en-
dowed with extraordinary virtues. Some of
it, brought to England, underwent a che-
mical examination, and proved, as nearly as
possible, pure flint. See Dr. Russell's and
Mr. Macie's papers on the subject in the Phil.
Trans, for 1 790 and 1791- It is even found
occasionally in the Bamboo cultivated in our
hot-houses. But we need not search exotic
plants for flinty earth. I have already, in
speaking of the Cuticle, chapter 3d, alluded
to the discoveries of Mr. Davy, Professor of
Chemistry at the Royal Institution, on this
subject. That able chemist has detected pure
flint in the cuticle of various plants of the fa-
mily of Grasses, in the Cane (a kind of Palm)
and in the Rough Horsetail, Equisetum hy-
emale, Engl. Bot. t. 915. In the latter it is
very copious, and so disposed as to make a
natural file, which renders this plant useful
in various manufactures, . for even brass can-
not resist its action. Common wheat straw,
when burnt, is found to contain a portion of

ODOUR OF PLANTS. 77

flinty earth in the form of a most exquisite
powder, and this accounts for the utility of
burnt straw in giving the last polish to mar-
ble. How great is the contrast between this
production, if it be a secretion, of the tender
vegetable frame, and those exhalations which
constitute the perfume of flowers ! One is
among the most permanent substances in
Nature, an ingredient in the primeval moun-
tains of the globe ; the other the invisible un-
tan° ible breath of a moment !

The odour of plants is unquestionably of a
resinous nature, a volatile essential oil, and
several phenomena attending it well deserve
our attentive consideration. Its general na-
ture is evinced by its ready union with spirits
or oil, not with water ; yet the moisture of
the atmosphere seems, in many instances,
powerfully to favour its diffusion. This I ap-
prehend to arise more from the favourable ac-
tion of such moisture upon the health and vi-
gour of the plant itself, thus occasionally pro-
moting its odorous secretions, than from the
fitness of the atmosphere, so circumstanced,
to convey them. Both causes however may
operate, ^i number of flowers which have no

78 NIGHT-SCENTED FLOWERS.

scent in the course of the day, smell power-
fully in an evening, whether the air be moist
or dry, or whether they happen to be exposed
to it or not. This is the property of some
which Linneeus has elegantly called jlores trim>
tes, melancholy flowers, belonging to various
tribes as discordant as possible, agreeing only
in their nocturnal fragrance, which is peculiar,
very similar and exquisitely delicious in all of
them, and in the pale yellowish, greenish, or
brownish tint of their flowers. Among these
are Mesembryanthemum noctiflorum. Dill.
Elth. t. 206, Pelargonium triste, Cornut.
Canad. 1 10, and several species "akin to it,
Hesperis tristis, Curt. Mag. t. 730, Chei-
ranthus tristis, t. 7^9, Daphne pontica, An-
drews s Repos. t. 73, Crassula odoratissima,
t. 26) and many others*. A few more, greatly
reseiirfelins: these in the green hue of their

* These flowers afford the poet a new image, which
is introduced into the following imitation of Martial,
and offered here solely for its novelty.

Go mingle Arabia's gums

With the spices all India yields.
Go crop each young flower as it blooms.

Go ransack the gardens and fields.

I

SMELL OF NEW HAY. 79

blossoms, exhale, in the evening chiefly, a
most powerful lemon-like scent, as Epiden-
drum ensifolium, Sm. Spicil. t. 24, and
Chloranthus inconspicuus> Phil. Trans, for
1787. t. 14, great favourites of the Chinese,
who seem peculiarly fond of this scent. There
are other instances of odorous and aromatic
secretions, similar among themselves, pro-
duced by very different plants, as Camphor.
The sweet smell of new hay is found not only
in Anthoianthum odor atum* Engl. Bot. t. 647,
and some other grasses, but in Woodruff or
Asperula odorata, t. 755, Melilot or Trifo-
lium officinale , t. 1340, and all the varieties,
improperly deemed species, of Orchis militaris y

Let Psestum's all-flowery groves

Their roses profusely bestow.
Go catch the light zephyr that roves

Where the wild thyme and marjoram grow.

Let every pale night-scented flower,

Sad emblem of passion forlorn,
Resign it's appropriate hour,

To enhance the rich breath of the mom.

All that art or that nature can find,
Not half so delightful would prove,

Nor their sweets all together combined,
Half so sweet as the breath of mv love.

80 BITTER-ALMOND FLAVOUR.

t. 1(), plants widely different from each other
in botanical characters, as well as in colour and
every particular except smell. Their odour has
one peculiarity, that it is not at all perceptible
while the plants are growing, nor till they
begin to dry. It proceeds from their whole
herbage, and should seem to escape from the
orifices of its containing cells, only when the
surrounding vessels, by growing less turgid,
withdraw their pressure from such orifices.
When this scent of new hay is vehement, it be-
comes the flavour of bitter almonds. The taste
of syrup of capillaire, given by an infusion of
Orange flowers, is found in the herbage of
Gaultheriaprocumbens^Andr. Repos. £.116,
and Spircea Ulmaria, Engl. Bot. t, 96O, two
very different plants.

Some of the above examples show an evi-
dent analogy between the smell and colours
of flowers, nor are they all that might be
pointed out. A variety of the Chrysanthe-
mum indicum with orange-coloured flowers
has been lately procured from China by Lady
Hume. These faintly agree in scent, as they
do in colour, with the Wall-flower, Ckeiran-
fhus Cheiri; whereas the common purple

ACRIMONY OF THE ARUM. 81

variety of the same Chrysanthemum has a
totally different and much stronger odour.

There is, of course, still more analogy be-
tween the smell of plants in general and their
impression on the palate, insomuch that we
are frequently unable to discriminate between
the two. The taste is commonly more per-
manent than the smell, but now 7 and then
less so. The root of, the Arum maculatum,
Engl. Bot. t. 1298, for instance, has, when
fresh, a most acrid taste and irritating qua-
lity, totally lost by drying, when the root
becomes simply farinaceous, tasteless and
inert; so that well might learned physi-
cians contrive the " Compound Powder of
Arum," to excuse the continuance of its use
in medicine, unless they had always prescri-
bed the recent plant. — Many curious remarks
are to be found in Grew relative to the tastes
of plants, and their different modes of affecting
our organs. Anatomy of Plants, p. 279 —
292.

To all the foregoing secretions of vegeta-
bles may be added those on which their vari-
ous colours depend. We can but imperfectly
account for the green so universal in their

82 COLOURS Of PLANT*.

herbage, but we may gratefully acknowledge
the beneficence of the Creator in clothing the
earth with a colour the most pleasing and the
least fatiguing to our eyes. We may be daz-
zled with the brilliancy of a flower-garden,
but we repose at leisure on the verdure of a
grove or meadow. Of all greens the most
delicate and beautiful perhaps is displayed by
several umbelliferous plants under our hedges
in the spring.

Some of Nature's richest tints and most
elegant combinations of colour are reserved
for the petals of flowers, the most transient
of created beings ; and even during the short
existence of the parts they decorate, the co-
lours themselves are often undergoing remark-
able variations. In the pretty little weed call-
ed Scorpion-grass, Myosotis scorpioides, EngL
Bot. t. 480, and several of its natural order, the
flower-buds are of the most delicate rose-
colour, which turns to a bright blue as they
open. Many yellow flowers under the influ-
ence of light become white. Numbers of
red, purple or blue ones are liable, from some
unknown cause in the plant to which they be-
long, to vary to white. Such varieties are

COLOURS OF PLANTS. 83

sometimes propagated by seed, and are al-
most invariably permanent if the plants be pro-
pagated by roots, cuttings or grafting. Plants
of an acid or astringent nature often become
very red in their foliage by the action of light,
as in Humeri Polygonum, Epilobium and
Berberis ; and it is remarkable that American
plants in general, as well as such European
ones as are particularly related to them, are
distinguished for assuming various rich tints
in their foliage of red, yellow, white or even
blue, at the decline of the year, witness the
Guelder-rose, the Cornel, the Vine, the Su-
mach, the Azalea pontica, Curt Mag. t. 433,
and others. Fruits for the most part incline
to a red colour, apparently from the acid they
contain. I have been assured by a first-rate
chemist that the colouring principle of the
Raspberry is a fine blue, turned red by the
acid in the fruit. The juices of some Fungi,
as Boletus bovinus and Agaricus deliciosus,
Sowerb. Fungi, t. 202, change almost instan-
taneously on exposure to the air, from yellow
to dark blue or green.

These are a few hints only on a subject
which opens a wide field of inquiry, and which,

g2

81 CSES OF- THE

in professedly chemical works, is carried to
a greater length than I have thought necessary
in a physiological one. See Thomsons Che-
mistry, v. 4, and IVilldenozJs Principles of
Botany, 229- We must ever keep in mind,
as we explore it, that our anatomical instru-
ments are not more inadequate to dissect the
organs of a scarcely distinguishable insect*
than our experiments are to investigate the
fine chemistry of Nature* over which the
living principle presides.

Before we take leave of the secreted fluids
of vegetables, a few more remarks upon their
direct utility to the plants themselves may
not be superfluous. Malpighi first suggested
that these secretions might nourish the plant,
and our latest inquiries confirm the sugges-
tion. Du Hamel compares them to the
blood of animals, and so does Darwin. But
the analogy seems more plain between the
sap, as being nearly uniform in all plants,
and the animal blood, as in that particular
they accord, while the secreted fluids are so
very various. Mr. Knight's theory confirms
this analogy, at the same time that it esta-
blishes the opinion of Malpighi. The sap

SECRETED FLUIDS. 8/)

returning from the leaf, where it has been
acted upon by the air and light, forming
new wood, is clear] v the cause of the increase,
of the vegetable body. But it is not so clear
how the resinous, gummy or other secretions,
laid aside, as it were, in vessels, out of the
great line of circulation, can directly minis-
ter to the growth of the tree. I conceive
they may be in this respect analogous to ani-
mal fat, a reservoir of nourishment whenever
its ordinary supplies are interrupted, as in
the winter, or in seasons of great drought,
or of unusual cold. In such circumstances
the mucilaginous or saccharine secretions
especially, perhaps the most general of all,
may be absorbed into the vegetable constitu-
tion ; just as fat is into the animal one, du-
ring the existence of any disease that inter-
rupts the ordinary supplies of food, or
interferes with its due appropriation. It is
well known that such animals as sleep through
the winter, grow fat in the autumn and
awake very lean in the spring. Perhaps the
more recent layers of wood in a Plum or
Cherry-tree, if they could be accurately exa-
mined, might be found to contain a greater

g6 USES OP THE

proportion of mucilage at the end of autumn,
than in the early spring. If these substances
do not nourish the plant, they seem to be
of no use to it, whatever secondary purposes
they may answer in the schemes of Provi-
dence. The direct end, with respect to the
plant, of the finer secreted fluids of its fruit
can very well be perceived, as tempting the
appetite of animals, and occasioning, through
their means, the dispersion of the seeds; and
the perfume of flowers may attract insects,
and so promote the fertilization of the seed,
as will be explained hereafter.

After what has been said we need not waste
much time in considering the hypothesis,
advanced by some philosophers, that the
sap-vessels are veins and the returning ves-
sels arteries. This is so far correct, that, as
the chyle prepared by the digestive organs,
poured into the veins and mixed with the
blood is, through the medium of the heart,
sent into the lungs to be acted upon by the
air; so the nutrimental juices of plants, taken
up from the earth, which has been called their
stomach, are carried by the sap-vessels into
the leaves, for similar purposes already men-

SECRETED FLUIDS. &7

tioned. The improved sap, like the vivid
arterial blood, then proceeds to nourish and
invigorate the whole frame. I very much
doubt, however, if those who suggested the
above hypothesis, could have given so satis-
factory an explanation of it.

That the secretions of plants are wonder-
fully constant appears from the operation of
grafting. This consists in uniting the branches
of two or more separate trees, as Dr. Hope's
willows, see p. 60, and a whole row of Lime-
trees in the garden of New College, Oxford,
whose branches thus make a network. This is
called grafting by approach. A more com-
mon practice, called budding, or inoculat-
ing, is to insert a bud of one tree, accom-
panied by a portion of its bark, into the bark
of another, and the tree which is thus engraft-
ed upon is called the stock. By this mode
different kinds of fruits, as apples, pears,
plums, (Sec, each of which is only a variety
accidentally raised from seed, but no further
perpetuated in the same manner, are multi-
plied, buds of the kind wanted to be propa-
gated being engrafted on so many stocks
of a wild nature. The mechanical part of

fig GRAFTING.

this practice is detailed in Du Hamel, Miller,
and most gardening books. It is of primary
importance that the liber, or young bark, of
the bud, and that of the stock, should be
accurately united by their edges. The air
and wet must of course be excluded.

It is requisite for the success of this opera-
tion that the plants should be nearly akin.
Thus the Chionanthus virginica, Fringe-tree,
■succeeds well on the Common Ash, Frax-
inas excelsior, by which means it is propa-
gated in our gardens. Varieties of the same
species succeed best of all ; but apples and
pears, -two different species of the same genus,
may be grafted on one stock. The story of
a Black Rose being produced by grafting a
common rose, it is not worth inquiring which,
on a black currant stock, is, as far as I can
learn, without any foundation, and is indeed
at the first sight absurd. I have known the
experiment tried to no purpose. The rose
vulgarly reported to be so produced is merely
a dark Double Velvet Rose, a variety, as we
presume, of Rosa centifolia. Another report
of the same kind has been raised concerning
the Maltese Oranges, whose red juice has

HEAT OF VEGETABLES. 89

been attributed to their being budded on a
Pomegranate stock, of which I have never
been able to obtain the smallest confirma-
tion.

Heat can scarcely be denominated a secre-
tion, and yet is undoubtedly a production,
of the vegetable as well as animal body,
though in a much lower degree in the former
than the latter. The heat of plants is evinced
by the more speedy melting of snow when
in contact with their leaves or stems, com-
pared with what is lodged upon dead sub-
stances, provided the preceding frost lias
been sufficiently permanent to cool those sub-
stances thoroughly. Mr. Hunter appears to
have detected this heat by a thermometer
applied in frosty weather to the internal parts
of vegetables newly opened. It is evident
that a certain appropriate portion of heat is a
necessary stimulus to the constitution of every
plant, without which its living principle is
destroyed. Most tropical plants are as effec-
tually killed by a freezing degree of cold, as
by a boiling heat, and have nearly the same ap-
pearance, which is exemplified every autumn
in the Garden Nasturtium, Trapaolum ma*

tyj FORCING OF PLANTS.

jus. The vegetables of eokl climates, on the
contrary, support a much greater degree of
cold without injury, at least while in a tor-
pid state ; for when their buds begin to ex-
pand they become vastly more sensible, as
is but too frequently experienced in the fickle
spring of our climate. Nor is this owing,
as vulgarly supposed, merely to the greater
power of the cold to penetrate through their
opening buds. It must penetrate equally
through them in the course of long and
severe winter frosts, which are never known
to injure them. The extremely pernicious
effects therefore of cold on opening buds can
only be attributed to the increased suscepti-
bility of the vital principle, after it has been
revived by the warmth of spring.

The vegetation of most plants may be
accelerated by artificial heat, which is called
forcing them, and others may, by the same
means, be kept in tolerable health, under a
colder sky than is natural to them. But
many alpine plants, naturally buried for
months under a deep snow, are not only ex-
tremely impatient of sharp frosts, but will not
'bear the least portion of artificial heat. The

HEAT OF THE ARUM, 01

pretty Primula marginata, Curt. Mag. i. 19%
if brought into a room with a fire when
beginning to blossom, never opens another
bud ; while the American Cowslip, Bode-
catheon Meadia, t. 12, one of the most hardy
of plants with respect to cold, bears forcing
admirably well.

Mr. Knight very satisfactorily shows, Phil.
Trans, for 1801, 343, that plants acquire
habits with regard to heat which prove their
vitality, and that a forced Peach-tree will
in the following season expand its buds pre-
maturely in the open air, so as to expose them
to inevitable destruction. See p. 56. A thou-
sand parallel instances may be observed, by
the sagacious gardener, of plants retaining the
habits of their native climates, which very
often proves one of the greatest impediments
to their successful cultivation.

The most remarkable account that has
fallen in my way concerning the production
of heat in plants, is that given by Lamarck in
his Flore Francohc, v. 3. 53S, of the Common
Arum maculatiim, Engl Pot. t. 1298, (the
white-veined variety), the flower of which,
at a certain period of its growth, he as-
8

92 HEAT OF THE. ARUM.

serts to be, for a few hours, " so hot as to
seem burning." The learned M. Senebier
of Geneva, examining into this fact, disco-
vered that the heat began when the sheath
was about to open, and the cylindrical body
within just peeping forth ; and that it was
perceptible from about three or four o'clock
in the afternoon till eleven or twelve at
night. Its greatest degree was seven of Reau-
mur's scale above the heat of the air, which
at the time of his observation was about
fourteen or fifteen of that thermometer.
Such is the account with which I have been
favoured by Dr. Bostock of Liverpool, from
a letter of M. Senebier*, dated Nov, 28.
1796, to M. De la Rive. I have not hitherto
been successful in observing the pheno-
menon in question, which however is well
worthy of attention, and may probably not
be confined to this species of Arum.

* It is now published in his Physiologie Vegelale,
v. 3. 314, where nevertheless this ingenious philosopher
has declared his opinion to be rather against the exist-
ence of a spontaneous heat in vegetables, and he ex-
plains even the above striking phaenomenon upon che-
mical principles, which seem to me very inadequate.

93

CHAPTER XL

THE PROCESS OF VEGETATION. USE OF
THE COTYLEDONS.

When a seed is committed to the ground
it swells by the moisture which its vessels
soon absorb, and which, in conjunction with
some degree of heat, stimulates its vital prin-
ciple. Atmospherical air is also necessary to
incipient vegetation, for seeds in general will
not grow under water, except those of aquatic
plants, nor under an exhausted receiver : and
modern chemists have determined oxygen
gas, which is always an ingredient in our at-
mosphere, to be absorbed by seeds in vege-
tation. An experiment is recorded in the
Philosophical Transactions, No. 23, of sow-
ing Lettuce-seed in two separate pots, one of
which was placed in the common air, the
other in the vacuum of an air-pump. In the

CJ4 PROCESS OF VEGETATION.

former the young plants rose to the height
of two inches, or more, in a week's time ; in
the other none appeared, till after the pot
had been removed for a similar period into
the air again. Seeds buried in the ground
to a greater depth than is natural to them
do not vegetate, but they often retain their
power of vegetation for an unlimited period.
Earth taken from a considerable depth will,
when exposed to the air, be soon covered with
young plants, especially of Thistles, or of the
Cress or Mustard kind, though no seeds have
been allowed to have access to it. If the
ground in old-established botanic gardens be
du^ much deeper than ordinary, it frequently
happens that species which have been long
lost are recovered, from their seeds being
latent in the soil, as I have been assured by
Mr. Fairbairn of Chelsea garden, and others.
The integuments of the seed, having ful-
filled their destined office of protection, burst
and decay. The young root is the first part
of the infant plant that comes forth, and by
an unerring law of Nature it is sent down-
wards, to seek out nourishment as well as to
fix the plant to the ground. In sea-weeds.

PROCESS OF VEGETATION.

F&ci, Ulvce and Conferva, it seems merely
to answer the latter purpose. In the Dodder,
Cuscuta, a parasitical plant, the original root
lasts only till the stems have established them-
selves on some vegetable, on whose juices they
feed by means of other roots or fibres, and
then withers away.

The descent of the root, and the ascent of
the leaf-bud in a contrary direction, are inge-
niously explained by Dr. Darwin, Vhjtologia
Sect. 9. 3, on the principle of the former
being stimulated by moisture, and the latter
by air, whence each elongates itself where it
is most excited. This is perhaps more satis-
factory than any mechanical hypothesis. In
whatever position seeds happen to lie in the
earth, the root makes more or less of a curve
in order to shoot downwards. Mr. Hunter
sowed a number of seeds in a basket of earth
placed on an axis, by which their position was
a little altered every day. After the basket
had thus made two or three circumvolutions,
the young roots were found to have formed
as many turns in attempting to attain their
natural perpendicular direction. Mr. Knight
has ascertained, Phil. Trans, for 1806, that

COTYLEDONS,

a strong centrifugal force applied to vegeta-
ting seeds will considerably divert the root
from this direction outwards, while the stem
i.seems to have a centripetal inclination.

The young root, if it grew in a soil
which afforded no inequality of resistance,
would probably in every case be perfectly
straight, like the radical fibres of bulbous
roots in water ; but as scarcely any soil is so
perfectly homogeneous, the root acquires an
uneven or zigzag figure. It is elongated
chiefly at its extremity*, and has always, at
that part especially, more or less of a conical
or tapering figure.

When the young root has made some pro-
gress, the two lobes, commonly of a hemisphe-
rical figure, which compose the chief bulk of
the seed, swell and expand, and are raised
out of the ground by the ascending stem.
These are called the Cotyledons. Between
them is seated the Embryo or germ of the
plant, called by Linnaeus Corculum or little
heart, in allusion to the heart of the walnut.

* As may be seen by marking the fibres of Hyacinth
roots in water, or the roots of peas made to vegetate in
wet cotton wool.

OF THE COTYLEDONS. 97

Mr. Knight denominates it the germen, but
that term is appropriated to a very different
part, the rudiment of the fruit. The expand-
ing Embryo, resembling a little feather, has
been for that reason named ty Linnoeus Plu-
mula ; it soon becomes a tuft of young leaves,
with which the young stem, if there be any,
ascends. Till the leaves unfold, and some-
times after, the cotyledons, assuming their
green colour, perform their functions ; then
the latter generally wither. This may be
seen in the Radish, Lupine, Garden Bean,
and various umbelliferous plants, in all which
the expanded cotyledons are remarkably dif-
ferent from the true leaves. Such is the ge-
neral course of vegetation in plants furnished
with two cotyledons, or dicotyledones; but I
have already mentioned a very distinct tribe
called monocolyledones, having but one. These
are the Grass and Corn tribe, Palms, the
beautiful Orchis family, and many others.
In these the cotyledon, or body of the seed,
does not ascend out of the ground, and some
have considered them as having no cotyledon
at all. See Mr. Salisbury's paper in the
Transactions of the Linnean Society, v. 7>

H

gg OF THE COTYLEDONS.

on the germination of the Orchis trihe. We
reserve more particular remarks on this sub-
ject till we examine the structure of seeds.

Some plants are reckoned by Linnaeus to
have many cotyledons, as the Fir and Cy-
press. But the germination of these differs
in no respect from that of the generality of
dicotyledones. Mr. Lambert, in his splendid
history of the genus Finns, has illustrated
this peculiarity of structure in the Swiss
P. Cembra; see our tab. I- fig* 2. In the
Dombeya, or Norfolk Island Pine, the cotyle-
dons are very distinctly four : see Jig. 3.

The preservation of the vital principle in
seeds is one of those wonders of Nature which
pass unregarded, from being every day under
our notice. Some lose their vegetative power
by being kept out of the ground ever so little
a while after they are ripe, and in order to
succeed must sow themselves in their own
way, and at their own time. Others may
be sent round the world through every vicis-
situde of climate, or buried for ages deep in
the ground, till favourable circumstances
cause them to vegetate. Great degrees of
heat, short of boiling, do not impair the ve-
2

OP THE COTYLEDONS. 99

getative power of seeds, nor do we know any
degree of cold that has such an effect. Those
who convey seeds from distant countries,
should be instructed to keep them dry ; for
if they receive any damp sufficient to cause
an attempt at vegetation, they necessarily die,
because the process cannot, as they are situ-
ated, go on. If, therefore, they are not ex-
posed to so great an artificial heat as might
change the nature of their oily juices, they
can scarcely, according to the experience of
Mr. Salisbury, be kept in too warm a place.
By the preservation of many seeds so long
under ground, it seems that long-continued
moisture is not in itself fatal to their living
powers ; neither does it cause their premature
germination, unless accompanied by some
action of the air.

It is usual with gardeners to keep Melon
and Cucumber seeds for a few years, in order
that the future plants may grow less luxuri-
antly, and be more abundant in blossoms and
fruit. Dr. Darwin accounts for this from the
damage which the cotyledons may receive
from keeping, by which their power of nou-
rishing the infant plant, at its first germina-

h 2

JOO OF THE COTYLEDONS.

tion, is lessened, and it becomes stunted and
dwarfish through its whole duration.

Dr. Thomson of Edinburgh, in his System
of Chemistry, xoh 4, .374, has published a
very satisfactory explanation of one part of
the functions of the cotyledons. Several phi-
losophers have discovered that very soon after
the seed begins to imbibe moisture, it gives
out a quantity of carbonic acid gas, even
though no oxygen gas be present. In this
case the process stops here and no germina-
tion takes place. But if oxygen gas be pre-
sent, it is gradually absorbed in the same
proportion. At the same time the farina of
the cotyledons becomes sweet, being convert-
ed into sugar. " Hence, it is evident," says
this, intelligent writer, " that the farina is
changed into sugar, by diminishing its car-
bon, and of course by augmenting the pro-
portion of its hydrogen and oxygen*. This
is precisely the process of malting, during
which it is well known that there is a con-
siderable heat evolved. We may conclude
from this that during the germination of

* This is also the opinion of M. de Saussure, Re-
cherches Chimiques surla Vegetation, p* 16.

OF THE COTYLEDONS. 101

seeds in the earth, there is also an evolu-
tion of a considerable portion of heat.
This indeed might have been expected, as
it usually happens when oxygen gas is ab-
sorbed. So far seems to be the work of che-
mistry alone ; at least we have no right to
conclude that any other agent interferes;
since hay, when it happens to imbibe moi-
sture, exhibits nearly the same processes."

I conceive the evolution of this heat may
powerfully further the progress of vegetation
by stimulating the vital principle of the em-
bryo, till its leaves unfold and assume their
functions. It is necessary to observe,
that the above process equally takes place,
whether the farinaceous particles be lodged in
the bulk of the cotyledons themselves, or
compose a separate body called by authors
the albumen, as in grasses and corn.

1CH

CHAPTER XII.

OF THE ROOT, AND ITS DIFFERENT
KINDS.

We begin the description of the completely
formed 'vegetable by its Root, as being the
basis of all the rest, as well as the first part
produced from the seed. Its use in general
is two-fold ; to fix the plant to a commodious
situation, and to derive nourishment for its
support. This part is therefore commonly
plunged deeply into the ground, having, as
we have already shewn, a natural tendency
to grow downwards. In some cases however,
when plants grow on the stems or branches
of others, as the Dodder or Cuscuta, several
Ferns, and a portion of the Orchis tribe,
the root is closely attached to the bark, from
which it draws nourishment, by the under
side only, the upper being bare.

The Root consists of two parts, Caudex>

OF THE ROOT, AND ITS DIFFERENT KIKDS. 103

the body of the Root, and Radicula the
fibre. The latter only is essential, being the
part which imbibes nourishment.

Roots are either of annual, biennial or
perennial duration. The first belong to plants
which live only one year, or rather one sum-
mer, as Barley ; the second to such as are
produced one season, and, living through the
ensuing winter, produce flowers and fruit
the following summer, as Wheat ; and the
third to those which live and blossom
through many succeeding seasons to an in-
definite period, as trees, and many herbaceous
plants. The term biennial is applied to any
plant that is produced one year and flowers
another, provided it flowers but once, whe-
ther that event takes place the second year,
as usual, or whether, from unfavourable cir-
cumstances, it may happen to be deferred to
any future time. This is often the case with
the Lavatera arborea, Tree Mallow, and
some other plants, especially when growing
out of their natural soil or station. Linnaeus
justly observes that however hardy with re-
spect to cold such plants may prove before
they blossom, they perish at the first ap-

101 OF THE ROOT,

proach of the succeeding winter, nor can any
artificial heat preserve them. This is, no
doubt, to be attributed to the exhaustion
of their vital energy by flowering. Several
plants of hot climates, naturally perennial
and even shrubby, become annual in our
gardens, as the Tropceohim, Garden Nastur-
tium.

In the Turnip, and sometimes the Carrot,
Parsnep, &c, the Caudex or body of the
root is above-ground and bare, becoming as
it were a stem. Linnseus indeed calls the
stems of trees " roots above-ground ;" but
this seems paradoxical and scarcely correct.
Perhaps it would be more accurate to say
the caudex is a subterraneous stem ; but we
rather presume it has functions distinct from
the stem, analogous, as has been hinted
p. 55, to digestion, at least in those plants
whose stems are annual though their roots
are perennial.

The fibres of the root, particularly those
extremities of them which imbibe nourish-
ment from the earth, are in every case strictly
annual. During the winter, or torpid season
of the year, the powers of roots lie dor-

AND ITS DIFFERENT KINDS. 105

mant, which season therefore is proper for
their transplantation. After they have begun
to throw out new fibres, it is more or less
dangerous, or even fatal, to remove them.
Very young annual plants, as they form
new fibres with great facility, survive trans-
plantation tolerably well, provided they re-
ceive abundant supplies of water by the
leaves till the root has recovered itself.

Botanists distinguish several different kinds
of roots, which are necessary to be known,
not only for botanical purposes, but as being
of great importance in agriculture and gar-
dening. The generality of roots may be
arranged under the following heads.

1. Radix fibrosa. A Fibrous Root. The most
simple in its nature of all, consisting only
of fibres, either branched or undivided,
which convey nourishment directly to the
basis of the stem or leaves. Many grasses,
asPoaannua, Engl. Hot. t. 1141, and the
greater part of annual herbs, have this kind
of root. The radical fibres of grasses that
grow in loose sand are remarkably downy,
possibly for the purpose of fixing them more

106 OF THE ROOT,

Securely to so slippery a support, or to mul-
tiply the surface or points of absorption in so
meagre a source of nutriment. The fibres
of some parasitical plants already alluded to,
chiefly of the beautiful genus Epidendrwn,
are peculiarly thick and fleshy, not only for
the purpose of imbibing the more nourish-
ment, but also to bind them so strongly to
the branches of trees, as to defy the force
of winds upon their large and rigid leaves.

2. Radix repens. A Creeping Root, as in
Mint, Mentha. A kind of subterraneous
stem, creeping and branching off horizon-
tally, and throwing out fibres as it goes.
This kind of root is extremely tenacious of
life, for any portion of it will grow. Hence
weeds furnished with it are among the
most troublesome, as the different sorts of
Couch-grass, Triiicum repens, Engl. Bot.
t. 909. iiolcus mollis^ t.ll 70, &c; while, on
the other hand, many sea-side grasses, hav-
ing such a root, prove of the most impor-
tant service in binding down loose blowing
sand, and so resisting the encroachments of
the ocean. These are principally Carex are-

AND ITS DIFFERENT KINDS. 107

toariu, Engl Bot. t . 928, Arundo armaria,
t. 520, and Elymus arenarius^ t. l6'72.

3. Radix fwifqrmis- A Spindle-shaped, or
Tapering Root. Of this the Carrot, Parsnep
and Radish are familiar examples. Such a
root is formed, on the principle of a wedge,
for penetrating perpendicularly into the
aground. It is common in biennial plants,

but not peculiar to them. The caudex,
which is the spindle-shaped part, abounds
with the proper secreted juices of the plant,
and throws out numerous fibres or radicles,
which are in fact the real roots, as they
alone imbibe nourishment.

4. Radix prtembrsa. An Abrupt Root, is
naturally inclined to the last-mentioned
form, but from some decay or interruption
in its descending point, it becomes abrupt,
or as it were bitten off. Scabiosa sitccisa,
Devifs-bit Scabious, Engl Bot. t. 878,
Hedi/pnois hirta, t. 555, and some other
Hawkweeds, have this kind of root, the old
opinion concerning which cannot be better
described than in Gerarde's Herbal, under
the plant first named, p. 726.

}08 OF THE ROOT,

" The great part of the root seemeth to
be bitten away : old fantasticke charmers
report, that the divel did bite it for envie,
because it is an herbe that hath so many
good vertues, and is so beneficial to man-

kinde." The malice of the devil has

unhappily been so successful that no virtues
can now be found in the remainder of the
root or herb.

5. Radio: taberosa. A Tuberous or Knobbed
Root, is of many different kinds. The
most genuine consists of fleshy knobs,
various in form, connected by common
stalks or fibres, as in the Potatoe, Solanum
tuberosum, and Jerusalem Artichoke*,
Helianthus tuberosus Jacq. Hort. Vind.
1. 161. These knobs are reservoirs of nou-
rishment, moisture, and vital energy. Se-
veral of the Vetch or Pea kind are furnished
with them on a smaller scale ; see Vicia
lathyroides, Engl BoU t. 30, and several

* A corruption, as I presume, of the Italian name
Girasole Articiocco, sun-flower Artichoke, as the plant
was first brought from Peru to Italy, and thence propa-
gated throughout Europe.

AND ITS DIFFERENT KINDS. 109

species of Trifolium, either annuals, as
glomeratum, t. 1063, or perennials, as
fragiferutn, t. 1050. — The knobs in
these instances are only of annual dura-
tion; in the Paeonia, Paeony, t . 1513, and
Spircea Filipendula, Drop wort, t. 284,
they are perennial. — In the Orchidece of
Europe they are mostly biennial. The
^root in many of the latter consists either
of a pair of globular or oval bodies, as
in Satyr aim hircinum, Engl. Bot. t. 34,
Oplmjs aranifera, t. 65, and apifera,
t. 383 ; or are palmate, that is, shaped
somewhat like the human hand, as in
Orchis maculata, t. 632. Of these glo-
bular or palmate knobs or bulbs one pro-
duces the herb and flowers of the present
year, withering away towards autumn,
♦and the other is reserved for the following
season, while in the mean time a third is
produced to succeed the latter. The knobs
of Ophri/s spiralis, t 541, are formed
three or four years before they flower, and
their flowering appears to be occasion-
ally deferred to a more distant period. The
root of Satyrium albidum, t. 505, consists

HO OF THE ROOT,,

of three pairs of tapering knobs or bulbs,
which flower in succession. On the contrary,
Ophrys manorokis, t. 7 1? forms its new bulb
so late that it is not perfected till the
autumn immediately preceding its flower-
ing, and the plant seems to have but one
bulb. Ophrys Nidus avis, t. 48, has clus-
ters of cylindrical knobs, which are formed,
and also wither away, in parcels, each
parcel being equivalent to one of the above-
mentioned bulbs.

Such of the Orchis tribe as have bien-
nial bulbs are supposed to be very diffi-
cult of cultivation, but according to the
experience of my excellent friend the late
Mr. Crowe, in whose garden I have seen
them many successive years, they are best
removed when in full flower, the earth
being cleared completely away from the
roots, which are then to be replanted in
their natural soil previously dried and
sifted. Afterwards they must be well
watered. The bulb for the following year
has not at the flowering period begun to
throw out its fibres, for after that happens
it will not bear removal. Sahjrium albidum

AND ITS DIFFERENT KINDS, 111

having, as mentioned above, so many pairs
of roots, the growth of some of which is
always going on, has hitherto not been
found to survive transplantation at all.

Iris tuberosa, Sm. FL Grcec. Sibth. U 41,
has a root very analogous to these just
described, but I.jlorentina and I germa-
nka, t. 39 and 40 of the same work, have
anore properly creeping roots, though so
thick and fleshy in their substance, and
so slow in their progress, that they are
generally denominated tuberous.

6. Radix bulbosa. A Bulbous Root, pro-
perly so called, is either solid, as in Crocus,
Lvia, Gladiolus, Sec; tunicate, tunicata,
composed of concentric layers enveloping
one another as in Allium, the Onion tribe ;
or scaly, consisting of fleshy scales con-
nected only at their base, as in LUium,
the White or Orange Lily. The two
latter kinds have the closest analogy with
leaf-buds. They are reservoirs of the vital
powers of the plant during the season when
those powers are torpid or latent, and in
order to perform the functions of roots, they
first produce fibres, which are the actual

112 OF THE ROOT,

roots. The strict affinity between bulbs and
buds appears from the scaly buds formed
on the stem of the Orange Lil} r , Lilium
bulbiferum, which fall to the ground, and,
throwing out fibres from their base, be-
come bulbous roots*. The same thing
happens in Dent aria bidbifera, Engl.
Bot. t. 309, and Saxifraga cernua, t. 664.
These two last-mentioned plants however
have scaly roots, like the Toothwort, Lath-
rcea Sqaamaria, t. 50, which seem bulbs
lengthened out. Whether they would, in
the torpid season of the year, bear removal,
like bulbs, we have no information. If
disturbed at other times they are immedi-
ately killed. Many plants with solid bulbs
are provided by Nature to inhabit sandy
countries, over the face of which, in the dry
season succeeding their flowering they are
scattered by the winds to a great distance,
as happens to our own Poa bulbosa, Engl.

* I have bad scaly buds form even on the flower-
stalk of LachenaUa tricolor. Curt. Mag. i. 82, whilst
lying for many weeks between papers to dry, which,
on being put into the ground, have become perfect
plants, though of slow growth.

AND iTS DIFFERENT &INDS. 113

Bot. L 1071, as well as to numerous beau-
tiful productions of the Cape of Good
Hope,

7. Radio: articulata, or granulata. A Jointed
or Granulated Root agrees very much
with those described in the last section,
The Oxalis Acetoseila,V?ood Sorrel, Engl.
Bot. t. 762, and Saxifraga granulata,
White Saxifrage, t. 500, are instances of it.
The former has most affinity with scaly
bulbs, the latter with solid ones.

It is evident that fleshy roots, whether of
a tuberous or bulbous nature, must, at all
times, powerfully resist drought. We have
already mentioned, p. 41, the acquisition of
a bulb in Phlenm pratense, Engl. Bot.
t. IO765 whenever that grass is situated in a
fluctuating soil, by which its vital powers are
supported while the fibrous roots are deprived
of their usual supplies. In this state it be-
comes the Phleum nodosum of authors; but
on bjing removed to a thoroughly wet soil,
it resumes the entirely fibrous root, and luxu-
riant growth, of PA. pratense. I have also
found Alopecurus geniculates, t. 1250, (an

1

114 OF THE ROOT,

aquatic grass, whose root is naturally fibrous
and creeping,) growing with an ovate juicy
bulb on the top of a dry wall. This variety
has been taken for the true A. bulbosus,
t. 1249? which has always bulbs even in
its native marshes. We see the wisdom of
this provision of Nature in the grasses above
mentioned, nor may the cause be totally
inexplicable. When a tree happens to grow
from seed on a wall, it has been observed,
on arriving at a certain size, to stop for a
while, and send down a root to the ground.
As soon as this root was established in the
soil, the tree continued increasing to a large
magnitude*. Here the vital powers of the
tree not being adequate, from scanty nou-
rishment, to the usual annual degree of in-
crease in the branches, were accumulated in
the root, which therefore was excited to an
extraordinary exertion, in its own natural
direction, downward. There is no occasion
then to suppose, as some have done, that the
tree had any information of the store of food

* A particular fact of this kind concerning an ash
was communicated to me by the late Rev. Dr. Walker
of Edinburgh. See also Trans* of Linn, Soc. v t 2. 2(58.

AND ITS DIFFERENT KINDS. 115

at the foundation of the wall, and volun-
tarily sent down its root to obtain it ; nor is
it wonderful that the Author of life should
provide for it as effectually as it could for
itself, had it really been a reflecting being.
So in the case of the grasses in question, I
presume the herb being in the first instance
starved, by a failure of the nutrimental fluids
hitherto conveyed by the water of the soil,
its growth would be checked, and when
checked the same growth could not, as we
know by observation on vegetation in general,
be instantaneously renewed. A sudden fresh
supply of food would therefore cause an accu-
mulation of vital energy in the root, which
would consequently assume a degree of vi-
gour and a luxuriant mode of growth not
natural to it, and become bulbous. Thus it
acquires a resource against such checks in
future, and the herb is preserved alive, though
in a very far less luxuriant state than when
regularly and uniformly supplied with its
requisite nourishment. These are not so-
litary instances. It is well worthy the atten-
tion of an intelligent cultivator to seek them
out, and turn them to his advantage.

i 2

116'

CHAPTER XIIL

DIFFERENT KINDS OF STEMS AND
STALKS OF PLANTS.

JL/iNNiEUS enumerates seven kinds of Trunks,
Stems, or Stalks of Vegetables. These are
necessary to be known, for botanical di-
stinctions, though some are more important
than others, both in that respect and in a
physiological point of view.

1. Caulis. A Stem properly so called, which
bears, or elevates from the root, the leaves
as well as flowers. The trunks and branches
of all trees and shrubs come under this de-
nomination, as well as of a great propor-
tion of herbaceous plants, especially an-
nuals.«

The Stem is either simple, as in the
White Lily, or branched, as in most
instances. When it is regularly and re-
peatedly divided, and a flower springs

OF THE STEM. 117

from each division, it is called caulis di-
chotomus, a forked stem, as in CI dor a
perfoliate!, Engl Bot. t. 60, as well as
the common Mouse-ear Chickweeds, Ce-
rastium vulgatum, £. 789? and viscosum,
t. 790.

Though generally leafy, a Stem may
be partially naked, or even entirely so in
plants destitute of leaves altogether, as
the Creeping Cereus, Cactus fiagelliformis y
Curt. Mag. t. 17? various exotic species
of Euphorbia or Spurge, and the whole
genus of Stapelia. In Qrobanche, it is
scaly, squamosus.

With respect to mode of growth, the

Stem is
Erectus 9 upright, as in Yellow Loosestrife,

Lysimachia vulgaris. Engl. Bot. t. 761.

Procumbens, procumbent, Wood Loosestrife,
L. nemorum, t. 527.

Repens, creeping, Creeping Loosestrife, JL
Nummularia, t. 528, and Creeping Crow-
foot, Ranunculus repens, t. 516.

Adscendens, ascending obliquely without sup-
port, as Panicum sanguinale, t. 849.

Prostratus, prostrate, or Depressus 9 de-
pressed, when it lies remarkably flat,

118 OF THE DIFFERENT

spreading horizontally over the ground,
as in Coldenia procumbens; also Corono-
pns Rue Hi i, Swine's-cress. Eng. Bot.
t. 1660.

Reclinatiis, reclining, curved towards the
ground, as in Ficus, the Fig, Rubus, the
Bramble, &c.

Radicans, clinging to any other body for
support, by means of fibres, which do
not imbibe nourishment, as Ivy, Hedera
Helix, Engl. Bot. t. 1267, Vitis quin-
quefolia, Sm. Insects of Georgia, t. 30.
Bignonia radicans, Curt. Mag. t. 485.
— Linnaeus, Philosophia Botanica 39,
has expressed this by the term repens,
but has corrected it in his own copy.
Still he does not distinguish between
these plants, and those whose stems throw
out real roots, which last only are justly
called creeping, whether they grow on
the ground, like those above mentioned,
or on other plants like Cuscuta, Dodder,
Engl. Bot. t. 55 and 378. See p. 95.

Scandens, climbing ; either with spiral
tendrils for its support, as the Vine, Vitis,
the various species of Passion-flower,
Passiflora ccerulea, Curt. Mag. I. 2&,

KINDS OF STEMS, 11*9

alata, t. 66, &c. and Bryonia dioica,
Red-berried Bryony, Engl. Bot. t. 439 ;
or by adhesive fibres, as in the preced-
ing paragraph.

Volubilis, twining round other plants by its
own spiral form, either from left to right,
supposing the observer in the centre, (or
in other words, according to the appa-

» rent motion of the sun,) as the Black
Bryony, Tamus communis, Engl. Bot.
t. 91, the Honeysuckles, Lonicera Ca-
prifolium, t. 799, and Periclymenum^
t. 800, and the Polygonum Convolvulus,
t. 941 ; or from right to left, contrary
to the sun, as the Great Bindweed, Con-
volvulus sepium, t. 313, the French
Bean, Phaseolus vulgaris, Ger. em,
1212, fig. 1, &c. — Figures of plants
being sometimes reversed by the en-
graver, in that case give a wrong repre-
sentation of the circumstance in ques-
tion, witness Lonicera Periclymenum in
Curtis's Elora Londinensis,fasc. 1. f. 15,
and many instances might be pointed
out of its not beiri£ attended to at all.

Flagclliformis, long and pliant, like tin*

120 OF THE DIFFERENT

Common Jasmine, Jasminum officinale,
Curt. Mag, t. 31, or Virginian Silk,
Periploca grceca, Fl. Graze, t. 249-

Sarmentosus, trailing. A creeping stem,
barren of flowers, thrown out from the
root for the purpose of increase, is
called sarmentum or fiagellum, a run-
ner, as in the Strawberry, Fragaria
vesca, Engl Bot. t. 1524. When leafy
it is generally denominated stolo, a
sucker or scyon, as in Bugle, Ajuga
reptans, t. 489, and Viola odorata, the
Sweet Violet, t. 619. When the stolo
has taken root, it sometimes flowers
the first year, see Curt. Fond. fasc. 1.
t. 63, but generally not till the follow-
ing season.

Rectus, straight, as in Lilium, the dif-
ferent species of garden Lily.

Strictus, expresses only a more absolute
degree of straightness.

Laxus or Diffusm, loosely spreading, has
a contrary meaning, as in Bunias Ca-
kile, Sea Rocket, Engl Bot. t. 231, and
Sedum acre, Biting Stone-crop, t. 839.

Fkxuosus, zigzag, forming angles alter-

KINDS OF STEMS. 121

irately from right to left and from left to
right, as in Smilax aspera, Ger, em.
859, and many of that genus, also St a-
tice reticulata, Matted Sea Lavender,
Engl. Bot. t. 328. In a less degree it is
not unfrequent. See A triplex peduncu-

lata, t, 232.
Alt erne ramosus, alternately branched, as
Polygonum minus, t. 1043, Dianthus
delloides, fc 61, &c.
Distichus, two-ranked, when the branches
spread in two horizontal directions, as in
the Silver Fir, Finns picea, Duhamel,
Arb, v. ht. 1.
JBrachiatus, brachiate, or four-ranked,
when they spread in four directions,
crossing each other alternately in pairs ;
a very common mode of growth in
shrubs that have opposite leaves, as the
Common Lilac, Syringa vulgaris.
Jtamosissimus,much branched, is applied to
a stem repeatedly subdivided into a great
many branches without order, as that of
an Apple or Pear-tree, or Gooseberry-
bush.
Vrolifer, proliferous, shooting out new

122 OF THE DIFFERENT

branches from the summits of the for-
mer ones*, as in the Scotch Fir, Pinus
sylvestris, Lambert's Pinus, t. 1. and Ly-
copodium annotinum, Engl. Bot. 1. 1727*
This is obsolete, and seldom used.

Determinate ramosus, abruptly branched,
when each branch, after terminating in
flowers, produces a number of fresh
shoots in a circular order from just below
the origin of those flowers. This term
occurs frequently in the later publications
of Linnaeus, particularly the second
Mantissa, but I know not that he has
any where explained its meaning. It is
exemplified in Azalea nudiflora. Curt.
Mag. t. 180, Erica TetralLr, Engl
Bot. t. 1014, many Cape Heaths, and
other shrubs of the same Natural Order.

Articulatus, jointed, as in Samphire, Sa-
licornia annua, Engl. Bot. t. 415, and
more remarkably in the Indian Figs,
Cactus Tuna, &c.

In shape the Stem is

Teres, round, as in Trollius europaus,

*Linn. Phil. Bot. sect. 82. 28.

KINDS OF STEMS. 123

Engl. Bot. t. 28, and Hydrangea hor-
temis, Sm. Ic. Pict. t. 12.
Anceps, two-edged, as Sisyrinchium stria-
tum, Sm. Ic. Pict. t. 9. S. gramineum,
Curt. Mag. t, 464, and some of the
genus Lathyrus.
Trigmms, or Triangularis, triangular or
three-edged, as Cactus triangularis,
Plukenet.t. 29./. 3.
Triqueter, three-sided, is applied to a stem

with 3 flat sides.
Tetragonus, or Quadrangular is, square,
as Lamium album, White Dead-nettle,
E?i<rl. Bot. t. ?68, and a multitude of
other plants.
Pentagonusy or Quinquangularis, five-
sided, as Asparagus horrid his , Cavanil-
les Ic. t. 136, where however the cha-
racter is not well expressed.

When the number of angles is either
variable, or more than five, it is usual
merely to describe the stem as angu-
losus, angular, except where the precise
number makes a specific difference, as
in the genus Cactus.
Alatus, winged, when the angles are ex-
tended into flat leafy borders, as Passi-
2

124 OF THE SURFACE

flora alata, Curt. Mag. t.66 9 Lathyrus
latifolius, Engl Bot. t. 1108, and many
others of the Pea kind, besides several
Thistles, as Carduus acanthoides, t. 973,
palustris, t. 974, and Centaurca solsti-
tialis, t. 243.

The Surface of the Stern is

Glaber, smooth, opposed to all kinds of
hairiness or pubescence, as in Petty-
Spurge, Euphorbia Peplus, Engl Bot.
t. 959, and numerous plants be-
sides.

Lcevis, smooth and even, opposed to all
roughness and inequality whatever, as
in the last example, and also Euonymus
europceus, t. 362.

Nitidus, polished, smooth and shining, as
Charophyllum syfoestre, t. 75 c 2.

Viscidus, viscid, covered with a clammy
juice, as Lychnis Viscaria, t. 788.

Verrucosus, warty, like Euonymus ver-
rucosus, Jacq. Fl Austriaca, t. 49,
and Malpighia volubilis, Curt. Mag.
t. 809.

Papillosus, papillose, covered with soft
tubercles, as the Ice plant, Mesem-

OF THE STEM. 125

brijantliemum crystallinum. DHL Elth.
t. 180.

Scaber, rough to the touch from any little
rigid inequalities, opposed to tavis, as
Caucalis Anthriscus, Engl But. t. 987,
Centaurea nigra, t. 278, and Stellaria
holostea, t. 511.

Ilispidus, bristly, as Borage, Borago offici-
nalis) t. 36, and Chara hispida, t. 463.

Hirius, or Filosuh hairy, as Salvia pra-
tensis, t. 153, and Cerastium alpinum,
t. 472.

Tomentosus, downy, as Geranium rotundi-
folium, t. 157, very soft to the touch.

Villosus, shaggy, as Cineraria integrifolia y
t. 152.

Lanatus, woolly, as Verbascum pulveru-
lentum, £.487, V. Thapsus, t. 549, and
Santolina maritima, t. 141.

Incanus, hoary, as Wormwood, Artemisia
Absinthium, t. 1230, and Atriplex
portulacoidesy t.26\, in the former case
from close silky hairs, in the latter from
a kind of scaly mealiness.

Glaucus, clothed with fine sea-green meali-
ness which easily rubs off, as Chlora

126 OP STEMS.

perfoliate!) t. 60 y and Pulmonaria ma-
ritimci) ^.368.

StriatiiSj striated, marked with fine pa-
rallel lines, as Oenanthejistulosa, t. 363.

Sulcatus, furrowed, with deeper lines, as
Smyr nium Olu$atrum t t. 230.

MaculatuS) spotted, as Hemlock, Conium
maculatuni) t. 1 191-

The spines and prickles of the stem will be
explained hereafter.

Internally the stem is either solidus, solid,
as that of Inula crithmoides, t. 68, and nume-
rous others I or cavus, hollow, as in Cineraria
palustrtS) t. 151, as well as Hemlock, and
many umbelliferous plants besides.

Plants destitute of a stem are called acaules,
stemless, as Neottia a caul is, Exot. Bot. t. 105,
and Carduus acaulis 9 Engl. Bot. t. l6l.
Such plants, when they belong to a genus
or family generally furnished with stems, as
in these instances and Carlina acauliS) Camer*
Epit. 428, are liable from occasional luxu-
riance to acquire some degree of stem, but
seldom otherwise. Pinguicula, Engl. Bot.
t. 70 and 145, is a genus invariably stemless,
while Primula, t. 4, 5, 6 and 513, is much

OF THE CULM. 1*7

less truly so. The term acaulis however
must never be too rigidly understood, for
logical precision is rarely applicable to natu-
ral productions.

Caulis fasciculatiis, a clustered stem, is a
disease or accident, in which several
branches or stems are united longitudi-
nally into a flat broad figure, crowded
with leaves or flowers at the extremity.
It occurs in the Ash, several species of
Daphne, Ranunculus, Antirrhinum, &c.
In a kind ofFisum, called the Top-knot
Pea, it is a permanent variety propa-
gated by seed.

2, Culm us. A Straw or Culm, is the
peculiar Stem of the Grasses, Rushes,
und plants nearly allied to them. It
bears both leaves and flowers, and its
nature is more easily understood than
defined. Many botanists have thought
this term superfluous.

The Culm is occasionally

Enodis, without joints, as in our common
Rushes, Juncus conglomtratus, EngL
But. t. 835, and effiusus, L 83G ;

128 OP THE STALK.

Articulatus, jointed, as in Agrostis alba.

t. 11S9, Aira cauescens, t. 1190, Avena

strigosa, t* 1266, and most other

grasses ;

Genicidatits, bent like the knee, asAlope-

curus geiiiculatus, t. 1250.
It is either solid or hollow, round or trian-
gular, rough or smooth, sometimes hairy or
downy, scarcely woolly. I know of no in-
stance of such a scaly culm as Linnaeus has
figured in his Philosophia Botanica, t. 4,
f. Ill, nor can I conceive what he had in
view.

3. Scapus. A Stalk, springs from the Root,
and bears the flowers and fruit, but not
the leaves. Primula vulgaris, the Prim-
rose, Engl. Bot. t. 4, and P. veris, the
Cowslip, t. 5, are examples of it. In
the former the stalk is simple and single-
flowered ; in the latter subdivided and
many-flowered. It is either naked, as in
Narcissus, EngL Bot. t. 17, or scaly, as
in Tussilago Farfara, t. 429. In others
of this last genus, t. 430 and 431, the

or THE FLOWER-STALK. 129

scales become leafy, and render the Sea-
pus a proper Caulk.

The Stalk is spiral in Cyclamen, Engl.
Bot. t. 548, and Valisneria spiralis, a won-
derful plant, whose history will be detailed
hereafter.

Linnaeus believed * that a plant could
not be increased by its Scapus, which in ge-
neral is correct, but we have already re-
corded an exception, p. 112, in Lachenalia
tricolor. The same great author has ob-
served -f that " a Scapus is only a species of
Pedunculns." The term might therefore be
spared, were it not found very commodious
in constructing neat specific definitions of
plants. If abolished, Pedunculus radicalism
a radical flower-stalk, should be substituted
in its room.

4. Pedunculus, the Flower-stalk, springs
from the stem, and bears the flowers and
fruit, not the leaves. Pedicellus, a par-
tial flower-stalk, is the ultimate subdivision
of a general one, as in the Cowslip, and
Saxifraga umbrosa, E/igL Bot. t. 6G3.

* MSS. in Phil. Bot. 40. f Ibid.

K

130 OF THE FLOWER-STALK*

The Flower-stalk is

Caulinus, cauline, when it grows immedi-
ately out of the main stem, especially
of a tree, as in Averrhoa Bilimbi,
Rumph. Amboin. v. L t. 36, the Indian
substitute for our green gooseberries.

Rameus, growing out of a main branch,
as in Averrhoa Carambola, ibid. t. 35,
and Eugenia malaccensis, Exot. Bot.

Axillaris, axillary, growing either from
the bosom of a leaf, that is, between it
and the stem, as Anchasa sempervirens,
Engl. Bot. t. 45, and Campanula
Trachelium, t. 12; or between a branch
and the stem, as Ruppia maritima,
t. 136.

Oppositifolius, opposite to a leaf> as Ge-
ranium pyrenaicum, t. 405, G. molle,
t. 778, and Slum angustifoliiim,
t. 139.

Internodis, proceeding from the interme-
diate part of a branch between two
leaves, as in Ehretia inter nodis, L'He-
ritierStirp. t. 24, Solatium carolinense,
DHL Hort. Eltlu t. 259, and indicum 9

OF THE FLOWER-STALK. 131

t. 260 ; but this mode of insertion is

rare.
Gemmaceus, growing out of a leaf-bud,

as the Barberry, Berber is vulgaris ,

Engl Boh t. 49.
Terminal-is, terminal, when it terminates

a stem or branch, as Tulipa sylvestris,

t. 63, and Centaurea Scabiosa, t. 56.
Lateralis, lateral, when situated on the

side of a stem or branch, as Erica

vagans, t. 3.
Solitarius, solitary, either single on a plant,

as in Rub us Chamcemorus, t. 716, or

only one in the same place, as in An-

tirrhinum spurium, t. 691, and many

common plants.
Aggregati Pedunculi, clustered flower-
stalks, when several grow together, as in

Verbascum nigrum, t. 59.
Sparsi, scattered, dispersed irregularly

over the plant or branches, as Linum

perenne, t. 40, and Ranunculus scele-

ratus, U 681.
Unifiori, biflori, triflori, &c. bearing one,

two, three, or more flowers, of which

examples are needless.
K 2

132 OF THE FLOWER-STALK.

Multifiori, many-flowered, as Daphne
Laureola, t. 11 9*

When there is no Flower-stalk, the flowers

are said to be Sessilcs, sessile, as in

Centaur ea Calcitrupa, t. 125, and the

• Dodders, t. 55 and 3/8.

The subject of inflorescence, or particular

modes of flowering, will be explained in a

future chapter.

5. Petiolus. The Footstalk, or Leaf-
stalk. This term is applied exclusively
to the stalk of a leaf, which is either
simple, as in Ranunculus parviflorus,
Engl. Hot. t. 120, Sium angustifoliuw,
t. 139, and all simple leaves ; or com-
pound, as Coriandrum sativum, t. 67, and
Fumaria claviculata, t 103. In the lat-
ter the footstalks end in tendrils, and are
called Petioli cirriferi.
This part is commonly channelled on the

upper side. Sometimes it is greatly dilated

and concave at the base, as in Angelica

sylvestris, t. 1128.

The Footstalk bears the Flower-stalk in

Turnera ulmifolia, Linn. Hort. Cliff', t. 10,

OF THE FROND. 133

Menyanthts fndica, Curt. Map;, h 658, and
perhaps Epimeduun alpinum, Engl. Bat.
t. 438.

6. Frons. A Frond. In this the stem,
leaf and fructification are united, or, in
other words, the flowers and fruit are
produced from the leaf itself, as in the
• Fern tribe, Scolopendrium vulgdre, Engl.
Bot. t. 1150, Po/ypodium vulgare, 1. 1149,
Aspidium, t. 1458 — 1401, Osmunda re-
galls, t. 209, &c. It is also applied to
the Lichen tribe, and others, in which
the whole plant is either a crustaceous or
a leafy substance, from which the fructifi-
cation immediately proceeds. Linnaeus
considered Palm-trees as fronds, so far
correctly as that they have not the proper
stem of a tree, see p. 58 ; but they are
rather perhaps herbs whose stalks bear the
fructification. It must however be ob-
served that the deposition of wood in ferns,
takes place exactly as in palms.

'J "he term frond is now used in the class
Cryptogamia only.

134 OF THE STIPE.

7. Stipes, Stipe*, is the stem of a frond,
which in ferns is commonly scaly. See
the plates cited in the last section. The
term is likewise applied to the stalk of a
Fungus, as the Common Mushroom,
Agariats campestris, Sowerbys Fungi,
t. 305.

* Marty n, Language of Botany ;.

135

CHAPTER XIV,

OF BUDS

Gemma, a Bud, contains the rudiments of
a plant, or of part of a plant, for a while in
a latent state, till the time of the year and
other circumstances favour their evolution.
In the bud therefore the vital principle is
dormant, and its excitability is accumulated.
The closest analogy exists between buds and
bulbs; and indeed the Dent aria bulbifera,
Engl. Bot. t. 309, Lilium bulbiferum, Jacq.
Fl. Austr. t. 226, and Gerarde emac. 193,
with other similar plants, as mentioned
p. 111, almost prove their identity.

Buds of trees or shrubs, destined for cold
countries, are formed in the course of the
summer in the bosoms of their leaves, and
are generally solitary ; but in the Blue-ber-
ried Honeysuckle, Lonicera ecerulea, Jacqi

136 OF BUDS.

FL Au&tr. append, t. 17, they grow one un-
der another for three successive seasons. The
buds of the Plane-tree, Platanus, Du Hamel
Arb. v. 2. 171 5 are concealed in the footstalk,
which must be removed before they can be
seen, and which they force off by their in-
crease ; so that no plant can have more truly
and necessarily deciduous leaves than the
Plane. Shrubs in general have no buds, nei-
ther have the trees of hot climates. Linna?us
once thought the presence of buds might
distinguish a tree from a shrub, but he was
soon convinced of there being no real limits
between them.

The situation of buds is necessarily like
that of the leaves, alternate, opposite, &c.
X v rees with opposite leaves have three buds,
those with alternate ones a solitary bud, at
the top of each branch. Du Hamel.

Buds are various in their forms, but very
uniform in the same species or even genus.
They consist of scales closely enveloping each
other, and enfolding the embryo plant or
branch. Externally they have often an ad-

iiqnal guard, of gum, resin or woolliness,
against wet and cold. The Horse Chesnut,

OF BUDS. 137

JEsculus Hippocasta?ium, now so common
with us 9 though, as I have learnt from Mr.
Hawkins*, a native of Mount Pindus in
Arcadia, is a fine example of large and well-
formed buds ; and some of the American
Walnuts are still more remarkable.

It has been already remarked, p. 90, that
buds resist cold only till they begin to grow :
hence, according to the nature and earhness
of their buds, plants differ in their powers of
bearing a severe or variable climate.

Grew is elaborate on the forms of buds,
and the arrangement of the spots apparent
within them when cut transversely, which
indicate the number and situation of their
vessels. It was the character of this excel-
lent man to observe every thing, without re-
ference to any theory, and his book is a
storehouse of facts relating to vegetation.
Loefling, a favourite pupil of Linnaeus, wrote,
under the eye of his great teacher, an essay
on this subject, published in the Amanitates
Acadaniccc, v. 2, in which the various forms
of buds, and the different disposition of the
* See a note on this subject, which Mr. R. P. Ktiight
has honoured with a place in the second edition of his
poem on Landscape.

138 OF BUDS.

leaves within them, are illustrated by nume-
rous examples. The Abbe de Ramatuelle
had taken up this subject with great zeal at
Paris, about twenty years ago, but the result
of his inquiries has not reached me.

Dr. Darwin, Phytologia, sect. 9, has many
acute observations on the physiology of buds,
but he appears to draw the analogy too closely
between them and the embryo of a seed, or
the chick in the egg. By buds indeed, as we
well know, plants are propagated, and in that
sense each bud is a separate being, or a
young plant in itself; but such propagation
is only the extension of an individual, and
not a reproduction of the species as by seed.
Accordingly, all plants increased by buds,
cuttings, layers or roots, retain precisely the
peculiar qualities of the individual to which
they owe their origin. If those qualities dif-
fer from what are common to the species,
sufficiently to constitute what is called a va-
riety, that variety is perpetuated through all
the progeny thus obtained. This fact is ex-
emplified in a thousand instances, none more
notorious than the different kinds of Apples,
all which are varieties of the common Crab,

OF BUDS. 139

Pyrus Mains, Engl Bot. t. 179; and I
cannot but assent to Mr. Knight's opinion,
that each individual thus propagated has only
a determinate existence, in some cases longer,
in others shorter; from which cause many
valuable varieties of apples and pears, known
in former times, are now worn out, and others
are dwindling away before our eyes. New
Varieties of Cape Geraniums, raised from seed
in our greenhouses, are of still shorter dura-
tion, and can be preserved by cuttings for a
few successive seasons only ; yet several of
these stand in our botanic works, with all the
importance of real species. Gardeners know
how many of the most hardy perennial herbs
require to be frequently renewed from seed
to exist in full vigour; and though others ap-
pear, to our confined experience, unlimited in
that respect, we have many reasons to be-
lieve they arc not so. Propagation by seeds
is therefore the only true reproduction of
plants, by which each species remains di-
stinct, and all variations are effaced ; for
though new varieties may arise among a
great number of seedling plants, it does not
appear that such varieties owe their pecu-

140 OF BUDS.

liarities to any that may have existed in the
parent plants. How propagation by seed is
accomplished will be explained in a future
chapter, as well as the causes of some va^
rieties produced by that means.

Mr. Knight, in the Philosophical Transac-
tions for 1805, has shown that buds origi-
nate from the alburnum, as might indeed be
expected. The trunks and branches of trees,
and the knobs of genuine tuberous roots, like
the potatoe, are studded with them ; in which
respect, as Professor Willdenow judiciously
observes, Principles of Botany, p. 15, such
roots essentially differ from bulbous ones,
which last are themselves simple buds, and
produce their shoots, as well as their offsets,
either from the centre or from the base.

The contents of buds are different, even
in different species of the same genus, as
Willows. The buds of some produce leaves
only, others flowers ; while in other species
the same bud bears both leaves and flowers.
Different causes, depending on the soil or
situation, seem in one case to generate leaf-
buds, in another flower-buds. Thus the
Solandra grandiftora, Tr. of Linn. Soc. v. 6.

OF BCD5. 141

99. L 6, a Jamaica shrub, was for a number
of years cultivated in the English stoves, and
propagated extensively by cuttings, each
plant growing many feet in length every sea-
son, from abundance of. moisture and nourish-
ment, without showing any signs of fructifi-
cation. At length a pot of the Solandra was
accidentally left without water in the dry
stove at Kew ; and in consequence of tins
unintentional neglect, the luxuriant grov
of its branches was greatly checked, and a
flower came forth at the extremity of each.
By a similar mode of treatment the same
effect has since frequently been produced.
Several plants, especially with bulbous roots,
which blossom abundantly in their native
soils, have hitherto defied all the art of our
gardeners to produce- this desirable effect;
yet future experience may possibly place it
within our reach by some v^ry simple means.
In general, whatever checks the luxuriant
production of leaf-buds, favours the forma-
tion of flowers and seeds. That variety, or
perhaps species, of the C Lily, I.iliuin

bulbif'erum, which is most pr< in bu ,

seldom forms ■ is

I4£ OF BUDS,

of the flower necessary to their perfection*
So likewise the seeds of Mints, a tribe of
plants which increase excessively by roots,
have hardly been detected by any botanist ;
and it is asserted by Doody in Ray's Synopsis,
that when the elegant little Ornithopus per-
pusillus, EngL Hot. t. 369, does not pro-
duce pods, it propagates itself by the grains
or tubercles of its root* though in general
the root is annual.

143

CHAPTER XV.

OF LEAVES, THEIR SITUATIONS, IN-
SERTIONS, SURFACES, AND VARIOUS
FORMS.

Folium, the Leaf, is a very general, but
not universal, organ of vegetables, of an ex-
panded form, presenting a much greater
surface to the atmosphere than all the other
parts of the plant together. Its colour is
almost universally green, its internal sub-
stance pulpy and vascular, sometimes very
succulent, and its upper and under surfaces
commonly differ in hue, as well as in kind or
degree of roughness.

Leaves are eminently ornamental to plants
from their pleasing colour, and the infinite va-
riety as well as elegance of their forms.
Their many occonomical uses to mankind,
and the importance they hold in the scale of

144 SITUATION AND POSITION OF LEAVES.

nature as furnishing food to the brute crea-
tion, are subjects foreign to our present pur-
pose, and need not here be insisted upon.
Their essential importance to the plant which
bears them, and the curious functions by
which they contribute to its health and in-
crease, will presently be detailed at length.
We shall first explain their different situa-
tions, insertions, forms, and surfaces, w r hich
are of the greatest possible use in systemati-
cal botany.

The leaves are wanting in many plants,
called for that reason plant a aphyllce^ as
Salicornia, Engl. Bot. t. 415 and 1691,
Stapelia variegata^ Curt. Mag. t. 26, glan-
duliflora, Exot. Bot. t. 71, and all the spe-
cies of that genus. In such cases the surface
of the stem must perform all their necessary
functions.

1. With respect to Situation and Position,
Folia radicalia, radical leaves, are, such as
spring from the root, like those of the
Cowslip, Engl. Bot. t. 5, and Anemone
Pulsatilla, t. 51.
Caulinay stem-leaves, grow on the stem

SITUATION AND POSITION OF LEAVES. 145

as in Paris quadrifolia, t. 7, Polemonium
cceruleiun, t. 14, &c.

Rarnea, branch-leaves, sometimes differ
from those of the main stem, and then
require to be distinguished from them,
as Melampyrum arvense, t. 53.

Alterna, alternate leaves, stand solitarily
on the stem or branches, spreading in
different directions, as those of Borage,
t. 36, and innumerable other plants.

Sparsa, scattered irregularly, as in Genista
tinctoria, t. 44, Lilium chalcedonicum,
Curt. Mag. t. 30, and bulbiferum, t. 36.

Opposita, opposite to each other, as Saxi-
fraga oppositifolia, Engl. Bot. t. 9,
Ballot a nigra, t. 46, &c.

Conferta, clustered, or crowded together,
as those of Trientalis europita, t. 15.

Bina, only two upon a plant or stem, as
in the Snowdrop, Galanthus nivalis^
t. 19, Scilla bifolia, t. 24, and Con-
vallaria majalis> t. 1035.

Terna, three together, as Verbena tri-
phylla, Curt. Mag. t. 367. The plants
of Chili and Peru seem particularly dis-
poned to this arrangement oi their leaves.

L

]4(J SITUATION AND POSITION OF LEAVES.

Quatema, quina, &c. when 4, 5, or more
are so situated, as in various species of
Heath, Erica.

Verticillata, whorled, is used to express
several leaves growing in a circle round
the stem, without a reference to their
precise number, as in Asperula cynan-
cAica, Engl. Bot. t. 33, and odorata,
U 755, which with the genus Galium,
and some others, are for this reason called
stellate star4eaved plants. Whorled
leaves are also found in Hippuris vul-
garis, t. 763, and many besides.

Fasciculata, tufted, as in the Larch, Pinus
Larix, Lamb. Pin. t. 35, the Cedar,
and some others of that genus.

Imbricata, imbricated, like tiles upon a
house, as in the common Ling, Erica
vulgaris, Engl Bot. t. 1013, and Eu-
phorbia paralia, t. 195.
Decussata, decussated, in pairs alternately
crossing each other, as Veronica de»
cussata, Curt. Mag. t. 242, and Me-
laleuca thy mi folia, Exot. Bot. t. 36.
Disticha, two-ranked, spreading in two
directions, and yet not regularly op-
2

SITUATION AND POSITION OP LEAVES. 147

posite at their insertion, as Pinus
canadensis. Lamb. Pin. t. 32, and
the Yew, Taxus baccata, Engl. Bot.
t. 746.

Secunda* unilateral, or leaning all towards
one side, as Convallaria multifiora^
t 279.

Adpressa, close-pressed to the stem, as
Xeranthcmum sesamoides, Curt. Mag.
t. 425.

Verticalia, perpendicular, both sides at
right angles with the horizon, as
Lactuca Scariola, Engl Bot. t. 268.

Erecta, upright, forming a very acute an-
gle with the stem, as J uncus articulatus,
t. 238.

Patc?itia, spreading, forming a moderately
acute angle with the stem or branch, as
Atriplcx portulacoidcSy t. 26l.

Jlorhontalia, horizontal, or patentmima,
spreading in the greatest possible de-
gree, as Oentiana campestris, t. 237.

Rcciinata, inclining downward, as Leo-
nuvm Cardiaca y t. 286.

liecurva, or reflexa, curved backward, as
Erica retortc, Curt. Mag, t. 362.
l 2

148 SITUATION AND POSITION OF LEAVES.

Incurva, or inftexa, curved inward, as
Erica empetrifolia, t. 447.

Obliqua, twisted, so that one part of each
leaf is vertical, the other horizontal, as
Fritillaria obliqua, t. 857, and some
of the large Frotece.

Resupinata, reversed, when the upper
surface is turned downward, as Fharus
latifolhts, Browne's Jamaica, t. 38,
Linn. Mss., and Ahtr&meria pelegrina,
Curt. Mag. t. 139.

Depressa, radical leaves pressed close to
the ground, as Flantago media, Engl.
Bot. t. 1559, and P. Coronopits, t. 892.
The same term applied to stem-leaves,
expresses their shape only, as being
vertically flattened, in opposition to
compress a. 4 *

Natantia, floating, on the surface of the
water, as ISfymphcea lutea, t. 159, and
alba, t. 160, also Folamogeton natans,
and many water plants.

Demersa, immersa, or submersa, plunged
under water, as Folamogeton perfoUa-
tuniy tt 168, Hottonia palustris, t. 364,
Lobelia Dortmaiwa, t. 140, and the

INSERTION OF LEAVES. i4&

lower leaves of Ranunculus aquatilis,
t. 101, while its upper &re folia natantia.
Emersa, raised above the water, as the
upper leaves, accompanying the flowers,
of Myriophyllum verticillaium, t. 218,
while its lower ones are demersa.

By Insertion is meant the mode in which
one part of a plant is connected with an-
other.

Folia petiolata, leaves on footstalks, are
such as are furnished with that organ,
whether long or short, simple or com-
pound, as Verba scum nigrum , Engl.
Bot. t. 59, Thalictrum minus, t. 11,
alpinum, t. 262, &c.
Peltata, peltate, when the footstalk is in-
serted into the middle of the leaf, like
the arm of a man holding a shield, as in
the Common Nasturtium, Tropceolum
majus, Curt. Mag. t. 23, Drosera pel-
tat a, Exot. Bot. t. 41, Cotyledon Um-
bilicus, Engl. Bot. t. 325, Hydrocotyle
vulgaris, £.751, and the noble Cyamus
Nelumbo, Exot. Bot. t. 31, 32.
Sessilia, sessile, are such as spring imme-

150 INSERTION OF LEAVES.

diately from the stem, branch or root,
without any footstalk, as in Ancliusa
sempervirens, Engl. Bot. t. 45, and
Pinguicula vulgaris, t. 70.
Amplexicaulia, clasping the stem with
their base, as the upper leaves of Glau-
cium luteum, t. 8, Gentiana campestris,
t. 237, and Humea elegans, Exot. Bot.
t. 1.
Comiata, connate, united at their base, as
Chlora perfoliate Engl. Bot. t. 60,
whose leaves are connato-perfoliata.
Perforata, perfoliate, when the stem runs
through the leaf, as Bupleurum rotundi-
folium, t. 99, and the Uvularue, Exot.
Bot. t. 49, 50, 51.
Vaginantia, sheathing the stem or each
other, as in most grasses ; see Phleum
alpinum, Engl. Bot. t. 5i9,nndArundo
arenaria^ t. 520. The same character
is found in many of the Orchis tribe, as
Satyrium albidum, t. 505.
Equitantia, equitant, disposed in two op-
posite rows and clasping each other by
their compressed base, as in Narthecium
ossifragum, t. 535, and the genus Iris;

PORfaS OF LEAVES. 151

also Witsenia corymbosa, Exot. Bot.
t. 68, and Dilatris corymbosa, t. 16.
Decurrentia, decurrent, running down the
stem or branch in a leafy border or
wing, as Onopordum Acanthium, Engl
Bot. t. 977, Carduus tenuiflorus, t. 412,
and many other Thistles, also the Great
Mullein, Verbascum Thapsus, t. 549,
and Comfrey, Symphytum officinale,

f. 817.
Florifera, flower-bearing, when flowers
grow out of the disk or margin of any
leaf, as in Ruscus aculeatus, t. 560,
Xylophylla latifolia, and JC. falcata,
Andr. Repos. t. 331. This is equivalent
to a frond in the class Cryptogamia ;
see p. 133.

With regard to form, Leaves are either
simplicia, simple, like those of Grasses,
Orchises, Lilies, and many other plants,
as Ballota nigra, Engl. Bot. t. 46, and
Berberis vulgaris, t. 49; or composite
compound, as in most Umbelliferous
plants, Parsley, Hemlock, &c. ; also
Roses, Engl Bot. t. 990—992.

152 FORMS OF LEAVES.

In compound leaves the footstalk is ei-
ther simple, as in the instances last
quoted, and Slum august if olium, 1. 139;
or compound, as those of Selinum pa-
lustre, t. 229, and Thalictrum majus,
t. 6*11. — In simple leaves the footstalk,
if present, must of course be simple,
while in compound ones it must always
be present, though not always sub-
divided.

Simple Leaves are either Integra, undi-

, vided, as those of Grasses and Orchises ;

or lobata, lobed, like the Vine, the

Thistle, most kinds of Cranesbill, as Ge-

ranium pratense, Engl. Bot. t. 404, &c.

Leaves are frequently undivided and lobed
on the same plant, as the Hop, Engh
Bot. t. 427.

4. The following are the most remarkable
forms of Simple Leaves, considering their
outline only,

Orbiculatum, a circular or orbicular leaf,
whose length and breadth are equal,
and the circumference an even circular
line. Precise examples of this are

FORMS OF LEAVES, 153

scarcely to be found. Some species of
Viper approach it, and the leaf of
liedysarum styracifolinm is perfectly
orbicular, except a notch at the base.

Subrotundum, roundish, as Pyrola, Engl.
Bot. t. 146, 158 and 213, and many
other plants.

Ovation, ovate, of the shape of an egg
cut lengthwise, the base being rounded
and broader than the extremity, a very
common form of leaves, as Urtica pilu-
lifer a, 1. 143, and Vinca major, t. 514.

Obovatum, obovate, of the same figure
with the broader end uppermost, as
those of the Primrose, t. 4, and the
Daisy, t. 424. Linnaeus at first used
the words obverse ovatum.

Ellipticum, or ovale, elliptical or oval, of
a similar form to the foregoing, but of
equal breadth at each end, as in the
Lily of the Valley, and other Conval-
larice, t. 1035, 2/9 and 280.

Oblongum, oblong, three or four times
longer than broad. This term is used
with great latitude, and serves chiefly
in a specific character to contrast a leaf

154 FORMS OF LEAVES.

which has a variable, or not very de-
cided, form, with others that are pre-
cisely round, ovate, linear, &c.

Spatulatum, spatulate, of a roundish fi-
gure tapering into an oblong base, as
in Silene Otites, Fl. Brit. Engl. Bot.
t.So.

Cuneiforme, wedge-shaped, broad and ab-
rupt at the summit, and tapering down
to the base, as in Saxifraga cunei folia.

Lanceolatum, lanceolate, of a narrow ob-
long form, tapering towards each end,
very common, as Tulipa syhestris^ EngL
Bot. t. 63, Lithospermum purpuro-
caruletim, t. 117, Plant ago la?iceolata>
t. 507 , many Willows, &c.

Linear e 9 linear, narrow with parallel sides,
as those of most Grasses ; also Genii ana
Pneumonanthe, t. 20, and Narcissus
Pseudo-narcissus, t. 17-

Acerosum, needle-shaped, linear and ever-
green, generally acute and rigid, as in
the Fir, Pinus, Juniper, Juniperus com-
munis, t. 1100, and Yew, Taxus bac-
cata 9 t. 746. Linnaeus observes, Phih
Bot. 219, that this kind of leaf has, for

FORMS OF LEAVES. 155

the most part, a joint at its union with
the branch.
Triangulares triangular, having three pro-
minent angles, without any reference to
their measurement or direction, as in
the genus Chenopodium, Cochlearia
danica, t 696, and some leaves of the

Ivy.

Quadrangulare, with four angles, as the
Tulip-tree, Liriodendrum tulipifera,
Sm. Ins. of Georgia, 1. 102. Curt. Mag.

t. 275.
Quinquangulare, with five angles, as some

Ivy leaves, &c.
Deltoides, trowel-shaped or deltoid, hav-
ing three angles, of which the terminal
one is much further from the base than
the lateral ones, as Chenopodium Bonus-
Henricus, Engl Bot. 1. 1033, and some
leaves of Cochlearia danica. A wrong
figure is quoted for this in Phitosophia
Botanica, which has caused much con-
fusion.
Bhombeum, rhomboid, or diamond-shaped,
approaching to a square, as Chenopodium
olidum, t. 1054, Trapa natans, Camcr.

156 FORMS OP LEAVES.

Epit. 715, and Trillium erectum, Curt,
Mag. t. 470.

Reniforme, kidney-shaped, a short, broad >
roundish leaf, whose base is hollowed
out, as Asarum europcsum, Engl. Bot.
t. 1083, and Sibthorpia europcea, t. 649.

Cor 'datum , heart-shaped, according to the
vulgar idea of a heart; that is, ovate
hollowed out at the base, as Tamus
communis, f..-9-L

Lunulatum, crescent-shaped, like a half-
moon, whether the points are directed
towards the stalk, or from it, as Passi-
flora lunata, Sm. Ic. Pict. t. 1.

Sagittatum, arrow-shaped, triangular, hol-
lowed out very much at the base, as
Sagittaria sagittifolia, Engl Bot. t, 84.
and Rumex Acetosa, t. 127-

Sometimes the posterior angles are cut
off, as in Convolvulus septum, t. 313.

Hastatum, halberd-shaped, triangular, hol-
lowed out at the base and sides, but
with spreading lobes, as Rumex Aceto-
sella, t. 1674, Antirrhinum Elatine,
t. 692, and the upper leaves of Solanum
Dulcamara, t. 565.

FORMS OP LEAVES. 157

Panduriforme, fiddle-shaped, oblong, broad
at the two extremities and contracted in
the middle, as the Fiddle Dock, Uumex
pulcher, t. 1576.
Runcinatum, runcinale, or lion-toothed,
cut into several transverse, acute seg-
ments, pointing backwards, as the Dan-
delion, Leontodon Taraxacum, t. 510.
Lyratum, lyrate, or lyre-shaped, cut into
several transverse segments, gradually
larger towards the extremity of the leaf,
which is rounded, as Erysimum Bar-
barm, t. 443.
Fissum, cloven, when the margins of the
fissures and segments are straight, as in
the Gingko-tree, Salisburia adiantifolia.
Bifid um 9 trifidum, multifidum 9 &c. ex-
press the number of the segments.
Lobatum, lobed, when the margins of the
segments are rounded, as in Anemone
Hepatka, Curt. Mag. t. 10.
Bilobum, tril&bum, &c, according to the
number of the lobes.
Sinuaium, sinuated, cut into rounded or
w: /;'<: ngs, as Statice sinuata 9 t.7l,

and Virgilia helioides, Eaoi. Bot. t. 37-

158 FORMS OF -LEAVES.

Fart Hum, deeply divided, nearly to the
base, as Helleborus viridis, JEngh Mot.
t. 200.

Bipartiiunu tripartitum y multipartitum+
according to the number of the divisions,

Laciniatum^ laciniated, cut into numerous
irregular portions, as Ranunculus pai*vi-
JloruS) t. 120, and Geranium columbi-
num> t. 259-

Incisum y and Dissect um, cut, are nearly
synonymous with the last.

It is remarked by Linnaeus that aqua-
tic plajits have their lower, and moun-
tainous ones their upper, leaves most
divided, by which they better resist the
action of the stream in one case, and of
wind in the other. Probably these ac-
tions arc in some measure the causes of
such configurations.

Palmatum, palmate, cut into several ob-
long, nearly equal segments, about half
way, or rather more, towards the base,
leaving an entire space like the palm of
the hand, as Passijlora carulea, Curt.
Mag. t. 28.

Tinnatifidunii pinnatifid, cut transversely

TERMINATIONS OF LEAVES. 159

into several oblong parallel segments, as
inlpomopsis, Exot. Bot. t. 13, 14, Bunias
Cakile, Engl. Bot. t. 231, Lepidium
didymum.t. 248, pctmum,t. Ill, and
Myriophyllum verticillatum, L 218.
Bipinnatifidum, doubly pinnatifid, as Fa-
paver Argcmone, t. 643, and Eriocalia
major i Exot. Bot. t. 78.
Pectinatum, pectinate, is a pinnatifid leaf,
whose segments are remarkably narrow
and parallel, like the teeth of a comb 7
as the lower leaves of Myriophyllum
verticillatum, and those of Hotionia
palustris, Engl Bot. t. 364.
Incequale, unequal, sometimes called ob-
lique, when the two halves of the leaf
are unequal in dimensions, and their
bases not parallel, as in Eucalyptus
resinifera, Exot. Bot. t. 84, and most
of that genus, as well as of Begonia.

5. The Terminations of Leaves are various.
Folium truncatum, an abrupt leaf, has the
extremity cut off, as it were, by a trans-
verse line, as Liriodendrum tulipifera,
Curt. Mag. t. 275.

1 60 TERMINATIONS OF LEAVES.

Pramorswn, jagged-pointed, very blunt*
vith various irregular notches, as in
Dr. Swartz's genus Aerides* compre-
hended under the Epidendrum of Lin-
neeus, See E. tessellation, RoxL PL
of Coromandel. t. 42, and pr amor sum ^

Retusum, retuse, ending in a broad shal-
low notch, as Rumex digynus, Engl.
Bat. t. 910.

Ernarginatum, emarginate, or nicked, hav-
ing a small acute notch at the summit,
as the Bladder Senna, Colutea arbores-
censy Curl. Mag. t. 81.

Obtusion, blunt, terminating in a segment
of a circle, as the Primrose, EngL Bot.
t. 4, Snowdrop, t. 19, Hypericum
quadrangulum, t. 370, and Linum
catharticum, t. 382.

Acutnm, sharp, ending in an acute angle,
which is common to a great variety of
plants, as Ladies' Slipper, 1. 1, Campa-
nula Trackeliurn, t. 12, and Linum
angustifoliiwi, t. 381.

Acuminatum, pointed, having a taper or
awlshaped point, as Arundo Phrag-

MARGINS OF LEAVES. \6l

mites, t. 401, and Scirpus maritimus,
t. 542.

Obtusum cum acumine, blunt with a small
point, as Stance Limonium, t. 102.

JMucronatum or Cuspidatum, sharp-point-
ed, tipped with a rigid spine, as in
the Thistles, t. 107, t. 386, &c, Rus-
cus aculeatus, t. 560, and Melaleuca
nodosa, Exot. Bot< t. 35.

Cirrosum, cirrose, tipped with a tendril,
as in Gloriosa superba, Andr. Repos.
t. 129-

The different Margins of Leaves are cha-
racterized as follows.

Eolium integer rimum, an entire leaf, as in
the Orchis and Lily tribe, as well as
Poli/gala vulgaris, Engl. Bot. t. 76,
Daphne Laureola, t. 119, &c.

This term is opposed to all kinds of
teeth, notches, or incisions. It regards
solely the margin of a leaf; whereas in-
tegrum, p. 152, respects its whole shape,
and has nothing to do with the man>iu.
English writers who translate the one
entire, and the other very entire arc
the re fo re i n c o rre c t .
M

*02 MARGINS OF LEAVES.,

Spinosum, spinous, beset with prickles,
as Carduus lanceolatus, t. 107, and
Eryngium campestrei t. 57« The veins
are spinous in Solatium Pyracantha,
Exot. Bot. U 64, &c.
Tnerme^ unarmed, is opposed to spinous.
CUiatum, fringed, bordered with soft pa-
rallel hairs, as Galium cruciatum, Engl.
Bot. t. 143.
Cartilagineum, cartilaginous, hard and
horny, as Saxifraga callosa, Dicks.
* Dr. PL n. 63.
Dentatum, toothed, beset with projecting,
horizontal, rather distant teeth of its
own substance, as Atriplex laciniata*
Engl. Bot. 1. 165, Hypochceris maculata,
/. 225, and the lower leaves of Centaur ea
CyanuSy t. 277 ; also Nymphaa Lotus,
Curt. Mag. t. 797-
Serratum, serrated, when the teeth are
sharp, and resemble those of a saw,
pointing towards the extremity of the
leaf. Examples of this are frequent, as
Urtica, t> 148 and 1236, Rosa, t. 992,
&c, Comarum palustre, t. 172, and Se-
necio paludosus, t. 650; also Dilknia
indicai Exot. Bot. t. 2. Some leaves

MARGINS OF LEAVES. 163

are doubly serrated, dupUcato-serrata,
having a series of smaller serratures in-
termixed with the larger, as Mespilus
grandiflora, t. 18, and Campanula Tra-
ckelium, Eng. Bot. t. 12.

Serrulatuni) minutely serrated, is used when
the teeth are very fine, as in Polygonum
amphibium, t . 436, and Emplcurum ser-
ralatum, Exot. Bot. t. 63.

Crenatum, notched, or crenate, when the
teeth are rounded, and not directed to-
wards either end of the leaf, as in Ground-
Ivy, Glechoma hederacea, t. 853, Chnj-
sosplenium, t. 54 and 490, and Sib-
thorpia eur opera, t. 649* In 8a xi frag a
Geum, t. 1561, the leaves are sharply
crenate. In the two British species of
Salvia, 1. 153 and 154, the radical leaves
are doubly crenate.

Er osum, jagged, irregularly cut or notched,
especially when otherwise divided be-
sides, as in Senecio squalid us , t. 600.

Bepandum. wavy, bordered with nume-
rous minute angles, and small segments
of circles alternately, as MenifantJics
nymphceoides, t. c 217, and Inula dysen-
teriotXi t* 1 1 15.

M 2

J 64 SURFACE OP LEAVES.

Glandalosum^ glandular, as Hypericum
montanum^ t. 371, and the Bay-leaved
Willow, SaliiV pentandra.
Revolutum, revolute, when the margin is
turned or rolled backwards, as Andro-
meda polifolia, t. 713, and Tetraiheca
glandulosa, Emt. Bot. t.2\.

Linnaeus seems originally to have ap-
plied this term to the rolling of the
whole leaf backwards, as in Solidago
Virgaurea, Engl BoL t. 301, meaning
to use the expression margin*, revolutum
when the margin was intended ; but
this latter case being extremely frequent
and the other very rare, he fell into the
practice of using revolutum simply for
the margin.
Involutum, involute, the reverse of the pre-
ceding, as in Pinguicula, t. 70 and
145.
CondupUcatum, folded, when the margins
are brought together in a parallel di-
rection, as in Jloscoca purpurea. ExoL
Bot. t. 108.
7- Terms expressive of different kinds of sur-
face, applying equally to the leaf and to
the stem, have been already explained,

SURFACE OP LEAVES. 165

p. 124. To these may be added the fol-
lowing, chiefly appropriated to leaves.
Punctatum, dotted ; either superficially as
in Rhododendrum punctatum, Andr.
Repos. t. 36, and Melaleuca fmari-
folia, Exot. Bot. t. 56 ; or through the
substance, as in Hypericum perforatum,
Engl Bot. t. 295, and the whole natu-
ral order to which the Orange and
Lemon belong.
Rugosum, rugged, when the veins are
tighter than the surface between them,
causing the latter to swell into little
inequalities, as in various species of
Sage, Salvia, See Flora Graca ; also
Teucrium Scorodonia, Engl. Bot. 1. 1 543.
Bui la turn, blistery, is only a greater de-
gree of the last, as in the Garden Cab-
bage, Brassica okracea.
Plication, plaited, when the disk of the
leaf, especially towards the margin, is
acutely folded up and down, as in Mal-
lows, andAlc/iemil/a vulgaris, Engl. Bot.
t. 597, where, however, the character
is but obscurely expressed.
Undulatum, undulated, when the disk near
the margin is waved obtusely up and

166 VEINS AND TUBS OF LEAVES.

down, as Reseda luiea, t. 321, and
Ilia crispa (more properly undulata*)
Curt, Mag. t. 599-

Crispum, curled, when the border of the
leaf becomes more expanded than the
disk, so as to grow elegantly curled and
twisted, which Linnaeus considers as a
disease. Malva crispa, Ger. em. 931,
is an example of it, and may probably
be a variety of M. verticillata, Jacq*
Hart. Find. v. 1. t . 40.

Concavum, hollow, depressed in the middle,
owing to a tightness in the border, as
Ci/amus Nchunbo, Exot. Hot. t. 32.

Vcnosuffl) veiny, when the vessels by which
the leaf is nourished are branched, sub-
divided, and more or less prominent,
forming a network over either or both
its surfaces, as Cratcegus, or rather
Fyrus, torminalis, Engl. Bot. t. 298,
and Verbascum Lychiiitis, t. 58.

Nervosum, or costatum^ ribbed, when they
extend in simple lines from the base to
the point, as in Cypripediuni Calceolus,
t. 1, the Convallarice, t. 279 and 280,
Stratiotes alismoides, Exot. Bot. t. 15,
* Salisb. Hort. 37-

VEINS AND RIBS OF LEAVES. 167

and Boxburghia viridiflora, t. 57. The
greater clusters of vessels are generally
called nervi or costcs, nerves or ribs., and
the smaller vena, veins, whether they
are branched and reticulated, or simple
and parallel.

Avenium, veinless, and e?ierve, ribless, are
opposed to the former.

Trinerve, three-ribbed, is applied to a leaf
that has three ribs all distinct from the
very base, as well as unconnected with
the margin, in the manner of those
many-ribbed leaves just cited, as Blakea
trinervis*, Curt. Mag. t. 451.

Basi trinerve, three-ribbed at the base, is
when the base is cut away close to the
lateral ribs, as in Burdock, Arctium
Lappa, Engl. Bot. t 1228, Tussilago,
t. 430 and 431, ar*d the great Annual
Sunflower,

Triplinerve, triply-ribbed, when a pair of
large ribs branch off from the main one
above the base, which is the case in

* Authors incorrectly use the termination trinprvius,
trinervia, &c. for the more classical trinervis, trinerve,
enervis, enerve.

168 VEINS AND RIBS OF LEAVES

many species of Sunflower or Helian-
thus, Laurus Cinnamomum and Cam-
phor a y as well as Blake a triplinervis,
Aublet Guian. t. 210.
Coloratum, coloured, expresses any colour
in a leaf besides green, as in Arum bi-
color, Curt. Mag. t. 820, Amaranthus
tricolor, and others of that genus, Jus-
iicia picta, Hedysarum pictwn, J acq.
Ic. Bar. t. 567, Tradescantia discolor,
Sm. Ic. Pict. t. 10, Pulmonaria offici-
nalis, Engl. Bot. tf. 118.

Variegation, variegated, is applied to a
sort of variety or disease, by which
leaves become irregularly blotched with
white or yellow, like those of Striped
Grass, A r undo color at a , Fl. Brit. ; as
also the Elder, the Mentha rotwidifolia,
Engl. Bot. t. 446, and the Aucuba ja-
ponica, which last is not known in our
gardens in its natural green state.

Nudum, naked, implies that a leaf is desti-
tute of all kinds of clothing or hairiness,
as in the genus Orchis. Nudus applied
to a stem means that it bears no leaves,
and to a flower that it has no calyx.

SUBSTANCE, &C. OF LEAVES. \f)Q

8. The following terms express the substance,
peculiar configuration, or any other re-
maining circumstances of leaves, not al-
ready explained.

Teres, cylindrical, as those of Concilium
gibbosum, White s Voyage, t. 22. f. 2 ;
see Cavanilles Icones, t. 533, and
534.
Semicylindraceum, semicylindrical, flat on
one side, as Salsola fructicosa, EngL
Bot. t. 635, and Chenopodium mariti-
mum, t. 633.
Subulatum, awlshaped, tapering from a
thickish base to a point, as Salsola Kali,
t. 634.
Tubuloswn, tubular, hollow within, as Al-
lium Cepa, the Common Onion. The
leaf of Lobelia Dortmanna, EngL Hot.
t. 140, is very peculiar in consisting of
a double tube.
Carnosum, fleshy, of a thick pulpy substance,
as in all those called succulent plants,
Crassula lactea, Exot. Bot. t. 33,
Aloe, Sedum, Mesembryanthemum, &c.
See Sempervivum tectorum, Engl. Bot.
t. 1320.
Gibbum, gibbous, swelling on one side or

170 SUBSTANCE, &C. OE LEAVES.

both, from excessive abundance of pulp_,
as Aloe retusa, Cart, Mag. t. 455.
Compressam, compressed, flattened late-
rally, as Mesembryanthemum uncina-
turn, DHL Elth. t. 193, and acinaci-
forme, t. 211.
Depressant, depressed, flattened vertically,
a.sM.li?iguiforme, t. 183—185. Seep. 148.
Canaliculatum, channelled, having a lon-
gitudinal furrow, as M. pugioniforme,
t. 210, Plant ago maritima, Engl Bot,
t. 175, and Narcissus poeticus, t, 275.
Carinatum, keeled, when the back is lon-
gitudinally prominent, as Narcissus bi*
floras t. 276.
Ensiforme, sword-shaped, is a two-edged
leaf, tapering to a point, slightly convex
on both surfaces, neither of which can
properly be called upper or under, as in
most of the genus Iris. See Cart. Mag.
t t 671, t. 9, &c, and EL Grtec. t. 39
and 40.
Anceps, two-edged, is much the same as

the last.
Acinaciforme, scimitar-shaped, compress-
ed, with one thick and straight edge,
the other thin and curved, as Mesem-

SUBSTANCE, &C. OF LEAVES. J 71

bryanthcmiun acinaciformc above-men-
tioned.

Bolabriforme, hatchet-shaped, compressed,
with a very prominent dilated keel, and
a cylindrical base, as M. dolabriforme.
Bill. Elth. t. 191, Curt. Mag. t. 32.

These two last terms might well be spared,
as they seem contrived only for the plants in
question, and indeed are not essentially di-*
siinct from each other.

Trigonwn, three-edged, having three lon-
gitudinal sides and as many angles, like
M. ddtoides, Bill Elth. i. 195, Linn.
Phil Bot. t. 1. f. 58. Linnreus has
erroneously referred to this figure to
illustrate his term deltoides ; misled, as
it should seem, by the name of the plan J
to wlaich it belongs; but his definition
is foreign to the purpose, aee p. 155,
and alludes to the outline of a flat leaf.

Triquetrum differs from trigomim only in
being used by Linnaeus for a three-sided
awl-shaped leaf, as M. emarginatum,
Bill Elth. t. 197, /. 250, and bko-
lorum, t. 2Q2, also Saaifraga burse-
riana.

Tctragonum, four-edged, having four pro.

J 72 SUBSTANCE, &CC. OF LEAVES.

minent angles, as Lis tuberosa, FL
GrcBc. t. 41.

Lingulatum, tongue-shaped, of a thick,
oblong, blunt figure, generally cartila-
ginous at the edges, as Mesembryan-
themam linguiforme, Dendrobium lin-
guiforme, Exot. Bot. t. 11, and several
species of Saxifrage, as S.mntata, Curt.
Mag. t. 351, S. Cotyledon, &c.

Membranaccmn, membranous, of a thin
and pliable texture, as in Aristolochia
Sipho, t. 534, Rubus odoratus, t. 323,
Magnolia purpurea, t. 390, &c.

Coriaceuftiy leathery, thick, tough and
somewhat rigid, as Magnolia grandi-
jlora, and Hydrangea hortensis, Sm. Ic.
Pict. 1. 12, Curt. Mag. t. 438.
Sempervirens, evergreen, permanent through
one, two, or more winters, so that the
branches are never stripped, as the Ivy,
the Fir, the Cherry Laurel, the Bay, &c.

Deciduum, deciduous, falling off at the
approach of winter, as in most European
trees and shrubs.

Alienatum, alienated, when the first leaves
of a plant give place to others totally
different from them and from the na-

SUBSTANCE, &X. OF LEAVES. 173

tural habit of the genus, as in many
Mimosce of New Holland ; see M. ver-
ticillata, Curt. Mag. t. 110, and mt/r-
tifolia, t 302 ; also Lathyrus Nissolia,
Engl. Bot. t. 112. The germination
of this last plant requires investigation,
for if its first leaves be pinnated, which
is probable, it is, exactly a parallel case
with the New Holland Mimosa.

Cuciillatum, hooded, when the edges meet
in the lower part, and expand in the
upper, as those of the curious genus
Sarracenia. See Curt. Mag. t. 730 and
849, and S. adunca^ Exot. Bot. t. 53.

Appe?idiculatum 9 furnished with an addi^
tional organ for some particular purpose
not essential to a leaf, as Dioncea mm-
clpula y Curt. Mag. t. 785, cultivated
very successfully by Mr. Salisbury, at
Brompton, whose leaves each terminate
in a pair of toothed irritable lobes, that
close over and imprison insects ; or Ne-
penthes distillatoria, Rumph. Amboin.
v. 5, t. 59, fi 2, the leaf of which bean?
a covered pitcher, full of water. Aldro-
vanda vesiculosa, and our Utricularice,
2

17 i SUBSTANCE, &X, OF LEAVES.

E?iqL Bot. t. 253, 254, have numerous
bladders attached to the leaves, which
seem to secrete air, and float the plants.
Many of the preceding terms applied to
leaves are occasionally combined to express a
form between the two, as ovato-lanceolatitm,
lanceolate inclining to ovate, or elliptico-lan-
ccolatum, as in the Privet, Engl. Bot. t. 764.
When shape, or any other character, cannot be
precisely defined, sub is prefixed to the term
used, as subrotimdum, roundish, subsessile*
not quite destitute of a footstalk, to which is
equivalent subpctiolatum, obscurely stalked.
By the judicious use of such means, all ne-
cessary precision is attained- It is to be
wished that authors were always uniform and
consistent, at least with themselves, in the
application of terms ; but as Linnaeus, the
father of accurate botanical phraseology, very
frequently misapplies his own terms, it is
perhaps scarcely to be avoided. I have ob-
served botanists most critical in theory, to be
altogether deficient in that characteristic
phraseology, that power of defining, which
bears the stamp of true genius, and which
renders the works of Linnaeus so luminous in

COMPOUND LEAVES. 175

despite of incidental errors. Perhaps no
mind, though ever so intent on the subject,
can retain all the possible terms of descrip-
tion and their various combinations, for ready
use at any given moment. There are few-
natural objects to which a variety of terms
are not equally applicable in description, so
that no two writers would exactly agree in
their use. Neither is Nature herself so con-
stant as not perpetually to elude our most
accurate research. Happy is that naturalist
who can seize at a glance what is most cha-
racteristic and permanent, and define all that
is essential, without trusting to fallacious,
though ever so specious, distinctions !

9. Folia composita, compound leaves, consist
of two or any greater number of foliola,
leaflets, connected by a common foot-
stalk.

Folium articulatum, a jointed leaf, is when
one leaflet, or pair of leaflets, grows
out of the summit of another, with a
sort of joint, as in Fagara tragodes,
Jacq. Amer. t. 14.

176 COMPOUND LEAVES.

Digitatum y digitate or fingered, when se-
veral leaflets proceed from the summit
of a common foot-stalk, as Potent ilia
verna, Engl. Bot. t. 37, reptans, t. 8ft2,
and Alchemilla alpina, t. 244.

Binatwn, binate, is a fingered leaf con-
sisting of only two leaflets, as in Zygo-
phyllum, Curt. Mag. t. 372.

Ternatum, ternate, consists of three leaf-
lets, as Fagonia cretica, t. 241, and
the genus Trifolium, Trefoil. See Engl.
Bot. t. 190, &c.

Quinatum y quinate, of five leaflets, as
Potent ilia alba, t. 1384, reptuns,
t. 862, &c.

Binnatum, pinnate, when several leaflets
proceed laterally from one foot-stalk,
and imitate a pinna tifid leaf, p. 158.
This is of several kinds.

cum imparl, with an odd, or terminal,
leaflet, as in Roses, and Elder, also
Polemonium cceruleum, Engl. Bot. 1. 14,
and Hedysarum Onobrychm, t. 9$.

cirrosum, with a tendril, when furnished
with a tendril in place of the odd leaf-

COMPOUND LEAVES* 177

let, as the Pea and Vetch tribe ; Pisum
maritimum, t. 1046, Lathyrus palustris,
t. 169, Vicia sativa, t. 334*
abrupte, abruptly, without either a termi-
nal leaflet or a tendril, as Cassia Chamce-
crista, Curt. Mag. t. 107, and the genus
Mimosa. See M. pudica, the Common
Sensitive-plant. This form of leaf is
much more uncommon than the imparl-
* pmnatum, and we have no perfect ex-
ample of it among British plants. The
nearest approach to it is the genus
Orobus, whose leaves have only the ru-
diments of a tendril. A truly wonder-
ful variety of the Orobus sylvaticus y
Engl Bot. t. 518, with large simple
leaves, has been found in Wales.

opposite, oppositely, when the leaflets are
opposite, or in pairs, as Saint-foin, t . 96,
Roses, Sium angustifolium, t. 139, &c.

alternatim, alternately, when they are
alternate, as Vicia dumetorum (Cracca
tyhatica) Riv. Pent. Irr. t. 51, and
occasionally in our V. sativa, lutea, &c.

interrupt^ interruptedly, when the prin-
cipal leaflets are ranged alternately with

N

I7S COMPOUND LEAVES,

an intermediate series of smaller = ones,
as Spircta Filipendula^EugLBot. £.284,
5. Uhnariciy t. 960, and Potentilla
&nserina, t. 861.

articulate, jointedly, with apparent joints
in the common footstalk, as Weinmannia
pinnaia.

decursive, decurrently, when the leaflets
are decurrent, as Eryngium campestre,
Engl Bot.t. 57, and Potentilla f rut i-
cosa, t. 88.

fyrato, in a lyrate manner, having the
terminal leaflet largest, and the rest
gradually smaller as they approach the
base, as Erysimum prcecox, t. 1129,
aiid, with intermediate smaller leaflets,
Geum rivale, t. 106'; also the Common
Turnip. Such leaves are usually denomi-
nated lyrate in common with those pro-
perly so called (whose shape is simple, and
not formed of separate leaflets); nor is
this from inaccuracy in botanical writers.
The reason is, that these two kinds of
leaves, however distinct in theory, are
of all others most liable to run into each
othei, even on the same ..plant; exam-

COMPOUND LEAVE*. 179

pies of which are frequent in the class
Tetr adynamia*
verticillato, in a whorled manner, the
leaflets cut into fine divaricated seg-
ments embracing the footstalk, as Sium
verticillatum, FL Brit. Engl. Bot. ft 395*
Auriculatum, an auricled leaf, is furnished
at its base with a pair of leaflets, pro-
perly distinct, but occasionally liable to
be joined with it, as Salvia triloba, FL
Grcec. t. 17, and Dipsacus pilosus,
Ensl. Bot. t. 877. Linnaeus in the last
example uses the term appendiculatum,
which is correct, but superfluous, and I
have therefore ventured to apply it
somewhat differently, p. 173*
Conjugatum, conjugate, or yoked, con-
sists of only a pair of pinnce or leaflets,
and is much the same as binatum. In-
stances of it are in the genus Zygophyl-
lum, whose name, equivalent to Yoke-
leaf, expresses this very character ; also
in Lathy rus sylvjstris, Engl. Bot. t. 80;%
and latifolius, t. 1103. ByugUfit, tri-
jugum,quadrijugitm 7 midtvjugum, &c,
express particular numbers of pairs'
N 2

ISO COMPOUND LEAVES.

of leaflets, and are used for that pur-
pose where such discrimination is requi-
site for specific characters, as in Mimosa .
The different degrees in which leaves are
compounded are thus distinguished,
without any reference to the mode.

Composition, simply compound, as in the
above instances.

Decomposition*, doubly compound, as
Athamanta Libanotis 9 Engl. Bot. £.138.
Mgopodium Podagraria, t. 940, and
Fumaria claviculata, t. 103.

Sapradecomppsitum 9 thrice compound, or
more, as Caucahs Anthriscus, t. 987,
C. daucoides, t. 197? and Bimium
fitxuontm^ t. 988. But

Bigeminatum, twice paired, as Mimosa
Unguis cati, Plum. Ic. t. 4; and terge-
minatum, thrice paired, as M. terge-
mina ; also

Biternaium, twice ternate, as Mgopodium,
Engl. Bot. t. 940 ; triternatiim, thrice
ternSte, as Fumaria lutea, t. 588 ; and

* Linnoeils, in Phil. Bot. 47, gives an erroneous defi-
nition of this term, which does not accord with his own
use of it. Professor Martyn has rightly defined it,

COMPOUND LEAVE3. 181

Bipinnatum y doubly pinnate, tripinna-

twn, triply pinnate, of which examples

have just been given : all apply to the

mode, as well as the degree, in which

leaves are compounded.

Pedatinn, pedate, is a peculiar kind of
leaf, being ternate, with its lateral leaf-
lets compounded in their fore part, as
Helleborus fatidus, Engl. Bot. t. 613,

* and H. niger, Curt. Mag. t. 8. There
is an affinity between a pedate leaf and
those simple ones which are three-ribbed
at the base, p. 167. See also the dis-
position of the lateral veins in Aristolo.
chia Ckmatith, Engl. Bot. L 398.

In compounding the foregoing terms we
must take care not to express a contradiction.
Thus the leaves of many Mimoscc, as the
purpurea, Andr. Repos. t. 3?2, and shisi-
tiva, are conjugata piimata, conjugate in
the first instance, pinnate in the next, not
conjugato-pinnata, of an intermediate nature
between conjugate and pinnate, which is im-
possible. Neither are the leaves of Mimosa

182 COMPOUND LEAVES.

pudica digitato-pinnata, for there is no me-
dium between the two terms ; but they are
digitate, or composed of leaflets proceeding
from the top of a common foot-stalk, and
those leaflets are pinnate. On the other hand
ovato-lanceolatu?n> lanceolate approaching to
ovate, or elliptico-Ianceolatum, approaching
to elliptic, as in the Privet, Engl. Bot. t. 764,
whose leaves often assume that shape, are
easily understood.

153

CHAPTER XVI.

OF THE FUNCTIONS OF LEAVES.,

X he knowledge of the functions of leaves,
and their real use with regard to the plant, is a
curious branch of vegetable physiology, which
made but a slow progress long after the na-
ture of many other parts had b.vn deeply
scrutinized and thoroughly explained.

Caesalpinus (De Ptantis, p. 6.) thought
leaves merely a clothing, or a protection
against cold and heat. He conceived that
the rays of the sun, being moderated in
passing through them, were prevented from
acting too violently on the fruit and ypumj
buds. " Accordingly," says he, u many
trees lose their leaves in autumn, when
their fruits are perfected, and their buds
hardened, while such as retain the fruit
long, keep also their leaves; even till a new

1S4 PERSPIRATION OF LEAVES.

crop is produced, and longer, as in the Fir;
the Arbutus, and the Bay. It is reported
that in hot climates, where there is almost
perpetually a burning sun, scarcely any
trees lose their leaves, because they require
them for shade/'' Caesalpinus goes on to
show that leaves proceed from the bark, ffifith
some remarks on the pith, (in which we may
trace the origin of the Linnaean hypothesis
of vegetation,) but which are now superseded
by more accurate inquiries.

The above is certainly a very small part of
the use of leaves. Yet the observations of
this writer, the father of botanical philosophy
among the moderns, are so far correct, that
if the leaves of a tree, be stripped off, the
fruit comes to nothing, which is exemplified
every year in Gooseberry bushes devoured by
caterpillars ; and though the fruit-trees of
warm climates, partly naturalized with us,
Grapes and Peaches for instance, ripen their
fruit sooner perhaps if partially deprived of
their leaves, yet if that practice be carried
too far, the fruit perishes, as gardeners who
tried it soon discovered. The White MirfV
berry indeed, cultivated in the south: of Eu-^

PERSPIRATION OP LEAVES. 185

rope for the food of silkworms only, bears
wonderfully the loss of its foliage three or
four times a year. How far the fruit is in-
jured nobody thinks it worth while to in-
quire, as it is never eaten, but it certainly
does not fall off prematurely.

That Leaves imbibe and give out moisture
has been long known, this being one of the
most obvious facts belonging to them. Dr.
Hales thought they might probably imbibe
air; but since his time more certain disco-
veries have been made concerning this point,
as well- as the effects of light upon leaves,
which also did not escape the consideration
of that great philosopher. All these subjects
w r e shall mention in their turn.

That Leaves give out moisture, or are or-
gans of insensible perspiration, is proved by
the simple experiment of gathering the leafy
branch of a tree, and immediately stopping
the wound at its base with mastick, wax, or
any other fit substance, to prevent the ef-
fusion of moisture in that direction. In a
very short time the leaves droop, wither and
are dried up. If the same branch, partly
faded, though not dead, be placed in a very

186 PERSPIRATION OP LEAVES.

damp cellar, or immersed in water, the leaves
revive, by which their power of absorption is
also proved. Hence the use of a tin box to
travelling botanists, for the purpose of re-
straining the evaporation of plants, and so
preserving them fresh for some days till they
can be examined, as well as of reviving faded
plants, if the inside of the box be moistened
before they are shut up in it.

Dr. Hales found that a plant of the Great
Annual Sunflower, Helianthus anniius, lost
lib. 14oz. weight in the course of twelve
hours in a hot dry day. In a dry night it
lost about 3 oz. ; in a moist night scarcely
any alteration was observable, but in a rainy
night it gained 2 or 3 oz. The surface of
the plant compared with that of its roots
was, as nearly as could be calculated, in the
proportion of five to two ; therefore the roots
must have imbibed moisture from the earth
of the pot in which the plant grew, and which
was all previously weighed, in the same pro-
portion of five to two, otherwise the leaves
would have faded. The same experiment
was made on the vine, the Cabbage, &c. ?
with various results as to the exact degree of

PERSPIRATION OF LEAVES. 18?

perspiration, but all proving it to be con-
siderable. Evergreens are found to perspire
much less than other shrubs.

The state of the atmosphere has a great
effect on the rapidity of this perspiration.
Practical botanists know how much sooner
plants fade, and haymakers experience how
much faster their work is done, some days
than others, and those days are by no means
always the most sunny. In a hot dry day
plants are often exhausted, so as to droop
very much towards evening, especially in the
dry unsheltered bed of a garden. Such as
have fleshy roots, indeed, have a singular
power of resisting drought, which has already
been explained p. 113. Succulent plants,
destined to inhabit sunny rocks, or sandy
deserts, imbibe with the greatest facility,
and perspire very sparingly. Evergreens are
not generally very succulent, but their cuti-
cle appears to be constructed like that of
succulent plants, so as to allow of little eva-
poration. The Cornelian Cherry, whose im-
mense perspiration we have recorded, p. 0'8,
has a thin dry leaf, capable of holding very
little moisture.

158 SEN5IBLE PERSPIRATION.

The nature of the liquor perspired has been
already noticed, p. 68. In hot weather it
has been observed by Hales, Du Hamel and
Guettard to partake occasionally of the pe-
culiar scent of the plant that yields it, but in
general the odorous matter is of too oily a
nature to be combined with it.

The sensible perspiration of plants is of
various kinds. When watery, it can be con-
sidered only as a condensation of their in-
sensible evaporation, perhaps from some sud-
den change in the atmosphere. Groves of
Poplar or Willow exhibit this phenomenon,
even in England, in hot calm weather, when
drops of clear water trickle from their leaves
like a slight shower of rain. Sometimes it is
of a saccharine nature, as De la Hire ob-
served in Orange trees ; Du Hamel Arb.
v. 1. 150. It is more glutinous in the Tilia
or Lime-tree, more resinous in Poplars, as
well as in Cistus creticus, from which last the
resin called Labdanum is collected, by beat-
ing the shrub with leather thongs. See
Tournefort's Voyage, 29. In the Fraxinella,
Dictamnm albas, it is a highly inflammable
vapour. Ovid has made an elegant use of the
4

SENSIBLE PERSPIRATION, 18Q

resinous exudation of Lombardy Poplars,
Populus dilatata, Ait. Hort. Kcw. v. 3.406,
which he supposes to be the tears of Phaeton s
sisters, who were transformed into those trees.
Such exudations must be considered as effu-
sions of the peculiar secretions ; for it has
been observed that Manna may be scraped
from the leaves of Fraxinus Omits, FL Grac.
t. 4, as well as procured by incision from its
stem. They are often perhaps a sign of un-
healthiness in the plant; at least such ap-
pears to be the nature of one kind of honey-
dew, to which the Beech in particular is sub-
ject, and which, in consequence of an un-
favourable wind, covers its leaves in the form
of a sweet exudation, similar in flavour to
the liquor obtained from its trunk. So like-
wi^e the Hop, according to Linnaeus, Fawn
Suec. 305, is affected with the honey-dew,
and its flowers rendered abortive, in conse-
quence of the attacks of the caterpillar of the
Ghost Moth, Fhalcena Hiimuli, upon its
roots. In such case the saccharine exudation
must decidedly be of a morbid nature*.

* I do not mean to dispute the accuracy of Mr. Cur-
tis's excellent paper, Tr, of Linn, Soc. v. 6, written to

IOO ABSORPTION OF LEAVES.

That wax is also an exudation from the leaves
of plants, appears from the experiments re-
corded by Dr. Thomson in his Chemistry,
v. 4, 298, and it has been long ago asserted
that wax may easily be gathered from the
leaves of Rosemary. On this subject I have
not made any experiments to satisfy my-
self.

With respect to the absorbing power of
leaves, the best observations that have beeix
made are those of Bonnet, recorded in the
beginning of his Recherches sur l' Usage des
Feuilles. His aim was., by laying leaves of
various plants upon the top of a jar of water,
some with their upper, and others of the
same species with their under, surfaces ap-
plied to the water, to discover in which situa-
tion the leaves of each plant continued longest
in health and vigour, and also how far dif-
ferent species differed from each other in this
respect. The results were in many instances
highly curious.

Of fourteen herbaceous plants tried by this

prove honey-dew to be the dung of dphides. I only
contend that there are more than one kind of honey-
dew.

ABSORPTION OF LEAVES. 19*

philosopher, six lived nearly as long with
one surface applied to the water as with the
other ; these were the common Arum macii-
latum, the French Bean, the Sun-flower,
Cabbage, Spinach and the Small Mallow.
By the last I presume is meant Malva ro-
tundifolia, Engl. Bot.t. 109 ( 2. Six others.
Plantain, White Mullein, the Great Mallow
(probably M. sylvestris, t. 671), the Nettle,
Cocks-comb, and Purple-leaved Amaranth
(probably Amaranthus hypocho?idriacit$),
lived longest with their upper surface laid
upon the water. The Nettle lived but three
weeks with its under surface on the water,
and about two months in a contrary position.
The Mullein scarcely survived five or six
days, and the Amaranth not a week, in the
first-mentioned posture, while the leaves of
the former remained m vigour about five
weeks, and of the latter three months, when
their upper surfaces imbibed the water.
Marvel of Peru and Balm, the two remain-
ing plants of the fourteen on which the ex-
periment was made, had also an evident ad-
vantage in receiving that fluid by their upper
surfaces. The leaves of some of the above

lg£ ABSORPTION Of LEAVES*

species were found to thrive better when their
stalks only were immersed in water, than
when either of their sides was supplied with
it, and the reverse was observable in several
others ; but the White Mullein, the Plantain
and the Amaranth survived longer when they
received the water by their stalk than by
their under surface, though not so long as
when it was applied to their upper sides.

Of sixteen trees tried by Bonnet, the Lilac
and the Aspen, Popidus tremula, were the
only leaves that seemed to imbibe water
equally well by either surface, whilst all the
others evidently succeeded best with their
under sides laid upon the water, being in
that respect the reverse of herbaceous plants.
Of these the White Mulberry leaf was the
most remarkable, not living more than five
days when supplied by the upper surface,
while such as floated on their backs continued
in perfection near six months. The Vine, the
Poplar (probably Populus nigra)> and the
Walnut, were no less remarkable, for fading
almost as soon, when fed by their upper sur-
face, as when left without any water at all.
Many of the other trees imbibed water as

ABSORPTION OF LEAVES. 193

well, or better, by their foot-stalks as by
their upper surfaces. Hazel-nut and Rose
leaves, when laid with their backs upon the
water, imbibe sufficiently to nourish other
leaves on the same branch ; so will one leaflet
of a French bean supply its neighbour that
does not touch the water.

Those who wish to repeat these experi-
ments should be careful to choose full-grown
healthy leaves, all as nearly as possible of
the same age and vigour. It is also desirable
that the precise species of plant should be
recorded by its scientific name. For want ot
this, Bonnet, who despised method and no-
menclature, has left us in uncertainty con-
cerning several of the plants he examined.
We ouo-ht to have been accurately informed

o

what species of Poplar differed so remarkably
in its power of absorption from the Aspen,
another of the same genus. We ought like-
wise to have been told what Sun-flower, what
Nettle, Amaranth and Mallows were exa-
mined ; for want of which information the au-
thority' of such experiments is much im-
paired.

From the forejroinsi* observation** we liini

194 OF AaUATIC PLANTS.

the importance of shading and watering plants
newly removed, cuttings, grafts, &c. and on
the other hand the benefit of heat and air to
promote due perspiration and evaporation.

The perspiration of aquatic plants seems to
be remarkably copious. Of these some gro\f
constantly immersed in the water, as most
species of Potamogeton, Pond-weed, Engl.
Bo', t. 168, 297, S?6, &c. Their leaves
are peculiarly vascular, and dry very quickly
in the air, withering in a very few r minutes
after exposure to it. Their absorbing power
seems equally great, so that they appear to
be continually, in their natural situation, im-
bibing and giving out a quantity of water,
much greater than has been observed in land
plants. Other aquatics, as the Nymphcea,
Engl. Bot. t. 159, 160, float with only the
upper surface of their leaves exposed to the
air, which surface is so contrived that water
will scarcely remain upon it. These leaves,
though extremely juicy, dry with great ra-
pidity, as does every part of the plants when
gathered. It is probable that they imbibe
copiously by their under sides, and perspire
by the upper.

SARRACENIA. 195

The oeconomy of the Sarracenia, an Ame-
rican genus of which we now know four spe-
cies, and of the East Indian Nepenthes di-
stillatoria, deserves particular mention. Beth
grow in bogs, though not absolutely in the
water. The former genus has tubular leaves
which catch the rain like a funnel and re-
tain it ; at least such is the nature of S. pur-
purea, Curt. Mag. t. 849, whose margin
seems dilated expressly for this purpose, while
the orifice of the tubular part just below is
contracted to restrain evaporation. Linnaeus
conceived this plant to be allied in constitu-
tion to Nymphcea, and consequently to re-
quire a more than ordinary supply of water,
which its leaves were calculated to catch and
to retain, so as to enable it to live without
being immersed in a river or pond. But the
consideration of some other species renders
this hypothesis very doubtful. S.Jiava, t. 780,
and more especially S. adunca, Eact. But.
t. 53, are so constructed that rain is nearly
excluded from the hollow of their leaves, and
yet that part contains water, which &eeni3 to
be secreted by the base of each leaf. What
then is the purpose of this; unusual ceil -~

)06 SARHACENIA.

vance ? An observation communicated to me
two years ago, in the botanic garden at Liver-
pool, seems to unravel the mystery. An in-
sect of the Spkex or Ichneumon kind, as far
as I could learn from description, was seen
by one of the gardeners to drag several large
flies to the Sarracenia adunca, and, with
some difficulty forcing them under the lid or
cover of its leaf, to deposit them in the tu-
bular part, which was half filled with water,
All the leaves, on being examined, were
found crammed with dead or drowning flies.
The S. purpurea is usually observed to be
stored with putrefying insects, whose scent is
perceptible as we pass the plant in a garden ;
for the margin of its leaves is beset with in^
verted hairs, which, like the wires of a mouse-
trap, render it very difficult for any unfor-
tunate fly i that lias fallen into the watery
tube, to crawl out again. Probably the air
evolved by these dead flies may be beneficial
to vegetation, and, as far as the plant is con-
cerned, its curious construction may be de-
signed to entrap them, while the water is
provided to tempt as well as to retain them.
The Sphex or Ichneumon, an insect of prey,

NEPENTHES. 197

•tores them up unquestionably for the food
of itself or its progeny, probably depositing
its eggs in their carcases, as others of the
same tribe lay their eggs in various cater-
pillars, which they sometimes bury after-
wards in the ground. Thus a double pur-
pose is answered ; nor is it the least curious
circumstance of the whole, that an European
insect should find out an American plant in a
hot-house, in order to fulfil that purpose.

If the above explanation of the Sarracenia
be admitted, that of the Nepenthes will not
be difficult. Each leaf of this plant terminates
in a sort of close-shut tube, like a tankard,
holding an ounce or two of water, certainly
secreted through the footstalk of the leaf,
whose spiral-coated vessels are uncommonly
large and numerous. The lid of this tube
either opens spontaneously, or is easily lifted
up by insects and small worms, who are sup-
posed to resort to these leaves in search of a
purer beverage than the surrounding swamps
afford. Rumphius, who has described and
figured the plant, says u various little worms
and insects crawl into the orifice, and die
in the tube, except a certain small sqailla

108 AIR-VESSELS OF THE LEAVES*

or shrimp, with a protuberant back, some-
times met with, which lives there/' — I
have no doubt that this shrimp feeds on the
other insects and worms, and that the spa
purposes are answered in this instance as in
the Sarracenice. Probably the leaves of
Dioncea muscipula, as well as of the Droser<z>
Engl, Bot. t. 867 — 869, catch insects for a
similar reason.

I proceed to consider the effects of Air and
Light upon vegetables,

Dr. Grew, by the assistance of the micro-
scope, detected a quantity of vesicles full of
air in the leaves of plants, as also the spiral-
coated vessels of their stems, which last he
and all other physiologists, till very lately,
considered as air-vessels likewise. Malpighi
made the same observations about the same
time ; and as these two acute and laborious
philosophers pursued their inquiries without
any mutual communication, their discoveries
strengthen and confirm each other. Their
books have long served as magazines of facts
for less original writers to work with. From
their remarks physiologists have theoretically
supposed that leaves imbibed air, which the

AIR-VESSELS OF THE LEAVES. 1$9

spiral vessels were believed to convey all
through the plant, in order that it might act
on the sap as it does on the animal blood.
The analogy thus understood was not correct,
because air is conveyed no further than the
lungs of animals ; but without this hypothesis
no use could be found for the supposed longi-
tudinal air-vessels.

The observations of Dr. Hales come next
in order to those of Grew and Malpighi. By
means of the air-pump, an instrument much
in use in his time, Hales obtained abundance
of air from every part of the vegetable body,
as well as from recently extracted sap. Plants
were found to perish very soon in an ex-
hausted receiver. Some of this great man's
experiments, however, require to be received
with caution. He rightly remarked that air
was not only taken in by plants very copious-
ly along with their food, but also imbibed
by their bark ; see Veg. Staticks^ chap. 5.
But when, from observing that it would
freely from the bark pervade the longitudi-
nal vessels of a branch, he concluded that
Malpighi and Grew were right in their ideas
of longitudinal air-vessels, he was misled by

200 AIR-VESSELS OF THE LEAVES.

appearances. We cannot tut be aware that,
when a branch is gathered, the sap must soon
flow out of those spiral-coated tubes, which are
large, elastic, and, no doubt, irritable. Af-
ter they are emptied, air may unquestionably
pass through them, especially when the whole
weight of the atmosphere is acting, as in
Dr. Hales's experiments with the air-pump,
upon so delicate a fabric as the internal
vascular structure of a plant, forcing its way
through pores or membranes not naturally
designed to admit it. We must also recol-
lect that a plant, cut even for a short time,
begins to lose its vital principle, after which
no just judgment can be formed, by any
experiments, concerning the movements of
its fluids in life and vigour. See Chapter 1.
These experiments of Dr. Hales therefore
prove no more than that the vegetable body
is pervious in various directions ; and per-
haps the only point they correctly establish
is, that air is imbibed through the bark, a
part known to be full of air-vessels. But the
seventh chapter of the Vegetable Staticks
contains some remarks much more to our
purpose. Dr. Hales there clearly anticipates

EFFECTS OF AIR ON LEAVES. £01

by conjecture, what succeeding philosophers,
more enlightened chemists, have ascertained.
His words are remarkable :
v. « \y e ma y therefore reasonably conclude,
that one great use of leaves is what has been
long suspected by many, viz. to perform in
some measure the same office for the support
of the vegetable life, that the lungs of ani-
mals do, for the support of the animal life ;
plants very probably drawing through their
leaves some part of their nourishment from
the air." p. 326. A little further on he
adds, " And may not light also, by freely
entering the expanded surfaces of leaves and
flowers, contribute much to the ennobling the
principles of vegetables :" p. 328.

Next in order of time to those of Hales
follow the experiments of Bonnet. We have
already detailed his observations on the
power of leaves to imbibe moisture ; whence
it is ascertained that plants are furnished with
a system of cuticular absorbents, which carry
fluids into their sap-vessels, so as to enable
them in some degree to dispense with sup-
plies from the root. . With respect to the
effects of air upon leaves, this ingenious

502 PURIFICATION OF AIR

philosopher has not been equally successful.
He is recorded as the discoverer of the expi-
ration of plants, but it appears from his
work that he merely observed the bubbles
of air which cling to leaves, dead as well as
living, and indeed to any other body, when
immersed in water and exposed to the light
of the sun. He found these bubbles disap-
peared in the evening, and returned again
when the sun shone, and he faithfully reports
that by their attachment to the surfaces of
leaves, the latter were rendered more buoyant,
and rose in the water ; a sure proof that the
air had not previously existed, in the same
volume at least, in the substance of those
leaves. Accordingly, Bonnet concluded that
the latter, in imbibing the surrounding water,
left the air which had been contained in the
water, and that this liberated air became
visible from being warmed and rarefied by
the sun. This was as near the truth as Bon-
net could come, it not being then known
that light has a power of separating air of a
peculiar kind, carbonic acid gas, from water.
I find no indications in his work of his having
had any idea of leaves absorbing air and

BY LEAVES. 203

giving it out again ; still less of their affecting
any change in its properties.

Dr. Priestley was the first who suggested
this last-mentioned quality in vegetables. He
ascertained their power of absorbing carbonic
acid gas, denominated by him fixed air, and
giving out oxygen gas, or pure respirable
air. It was also his opinion that leaves im-
bibed the former by their upper, and gave
6ut the latter by their under surface. He
found some aquatic or marsh plants extremely
powerful in this respect, especially the Wil-
low-herb or Epilobium, and the Conferva, a
minute branching cotton-like vegetable which
grows in putrid water, and the production of
which, in water become foul from long keep-
ing on ship-board, Dr. Priestley judged to
operate principally in restoring that fluid to
a state fit for use.

Dr. Ingenhousz, pursuing Dr. Priestley's
inquiries, found light to be necessary to
these functions, and that in the dark leaves
gave out a bad air. He observed moreover
that fruits and flowers almost invariably gave
out a bad, or carbonic, air, but more espe-
cially in the dark. He probably carries his

204 PURIFICATION OF AIR

ideas, of the deleterious effects of this air
on animal life, too far ; for no mischief has
ever happened, as far as common experience
goes, to persons sleeping in apple or olive
chambers, neither do the inhabitants of the
confined huts in Covent-garden market appa-
rently suffer, from living day and night
among heaps of drying herbs. Mischiefs
have unquestionably arisen from flowers in
a bed-room, or any other confined apartment,
but that is to be attributed to their perfumed
effluvia. So the bad effects, observed by
Jacquin, of Lobelia longiflora on the air of a
hot-house, the danger incurred by those who
sleep under the Manchineel-tree, Hippomanc
Mancinella^ or, as it is commonly believed,
under a Walnut-tree, are probably to be at-
tributed as much to poisonous secretions as
to the air those plants evolve.

Dr. Ingenhousz introduced leaves into glass
jars filled with water, which he inverted in a
tub of the same water, and placed the whole
together in the sun-shine. From their under
sides came streams or bubbles of air, which
collected in the inverted bottom of each jar.
The air thus procured proved oxygen gas,

BY LEAVES. 205

more or less pure. The 'Nymphcea alba^ Engl.
Bat. ti l60, affords an extraordinary abun-
dance of it. Dr. Ingenhousz observed plants
to be very various in their mode of emitting
these bubbles, but it was always uniform in
the same species. Air collected from water
placed in similar circumstances without plants,
proved not oxygen, but much worse than
common air, viz. carbonic acid gas, which
following chemists have confirmed, and which
we have already mentioned. Ingenhousz also
found the air collected from plants under
water in the dark worse than common air,
especially that from walnut-leaves ; which
confirms the common opinion, above alluded
to, respecting this tree.

Plants purify air very quickly. A vine-
leaf in an ounce phial of carbonic acid gas,
that immediately extinguished a candle,
placed in the sun, without watery changed it
to pure respirable air in an hour and half.
Dr. Priestley found plants to alter even un-
mixed inflammable air, or hydrogen, espe-
cially the Epilobium liirsutum, if I mistake
not, and Polygonum Ilydropiper.

Succulent plants are found to afford most

206 EFFECT OF LIGHT UPON PLANTS.

air, in consequence of the abundance of their
Cellular Integument, or ParencJn/ma.m which,
as I have hinted in the fourth chapter, the
chemical operations of the leaves are performed.
That Light has a very powerful effect upon
plants has lohg been known, independent oi
the remarks of Hales or Ingenhousz. The
green colour of the leaves is owing to it, in-
somuch that plants raised in darkness are of
a sickly white. It has even been observed
that when light is admitted to the leaves
through different glasses, each tinged of a
different prismatic colour, the plant is paler
in proportion as the glass approaches nearer
to violet. The common practice of blanch-
ing Celery in gardens, by covering it up
from the light, is an experiment under the
eyes of every one. This blanching of plants
is called by the French etiolation, and our
chemists have adopted the term, though I
think they err in deriving it from etoile, a
star. When blanched plants are brought
into the light, they soon acquire their natu-
ral green colour, and even in the dark they
are green, if exposed to the action of hydro-
gen gas. Tulip and Crocus flowers have long

TURNING OF LEAVES TO THE LIGHT* 207

ago been observed by Sennebier to be co-
loured even in the dark, apparently because
their colour depends on a different principle
from the green of leaves.

Light acts beneficially upon the upper sur-
face of leaves, and hurtfully upon the under
side ; hence the former is always turned to-
wards the light, in whatever situation the
plant may happen to be placed. Trees nailed
against a north wall turn their leaves from
the wall, though it be towards the north, and
in direct opposition to those on a southern
wall over against them. Plants in a hot-
house all present the fronts of their leaves,
and this influences even the posture of the
branches, to the side where there is most
light, but neither to the quarter where most
air is admitted, nor to the flue in search of
heat. If the branches of a trained fruit-tree
in full leaf be disturbed in their position, the
leaves resume their original direction in the
course of a day or two. The brighter the
day, the more quickly is this accomplished.
If the experiment be often repeated, they
continue to turn, but more weakly, and are
much injured by the exertion. Black sj >tl

80S TURNING OF FLOWERS TO THE LIGHT.

appear about the veins on their under sides,
and the cuticle scales off. Succulent leaves,
though so thick and firm as many of them
"are, have been observed to be peculiarly sen-
sible to light, while other plants, as Mallows,
according to Bonnet, are much less so. The
Miseltoe, Viscum album, Engl. Bot. 1. 1470,
the two sides of whose leaves are alike in ap-
pearance, and both equally, in general, pre-
sented to the light, are not found to turn
upon any change in the posture of the branch.
Neither do upright sword-shaped leaves alter
their position, because in them both sides
must be presumed to perform the same func-
tions with respect to light as well as air.

Mr. Calandrini found vine-leaves turned
to the light when separated from the stem
and suspended by a thread. Of this any
one may be easily satisfied, provided the ex-
periment be made with sufficient care and
delicacy. It is important, as demonstrating
the turning to be accomplished by an im-
pression made on the leaf itself, and not upon
its footstalk. -

Nor is this effect of light peculiar to leaves
alone. Many flowers are equally sensible to

TURNING OP FLOWERS TO THE LIGHT. £09

it, especially the compound radiated ones, as
the Daisy,- Sun-flower, Marigold, &c. In
their forms Nature seems to have delighted
to imitate the radiant luminary to which they
are apparently dedicated, and in the absence
of whose beams many of them do not expand
their blossoms at all. The stately Annual
Sun-flower, Helianthus annum, displays this
phenomenon more conspicuously on account
of its size, but many of the tribe have greater
sensibility to light. Its stem is compressed
in some degree, to facilitate the movement of
the flower, which, after following the sun all
day, returns after sun-set to the east, by its
natural elasticity, to meet his beams in the
morning. Dr. Hales thought the heat of the
sun, by contracting the stem on one side, oc-
casioned the flower to incline that way ; but
if so, it would scarcely return completely at
night. There can be no doubt, from the ob-
servation of other similar flowers, that the
impression is made on their radiated florets,
which act as wings, and seem contrived chiefly
fof that purpose, being frequently destitute
of any other use. A great number of leaves

p

v

£10 SLEEP OF FLANTS.

likewise follow the sun in its coarse ; a clover-
field is a familiar instance of this.

Of all leaves those of pinnated leguminous
plants are found most affected by light, inso-
much that it appears, in several cases, the sole
cause of their expansion, for when it is with-
drawn they fold over each other, or droop,
as if dying ; and this is called by Linnaeus the
Sleep of Plants, who has a dissertation on the
subject in his Amcenitates Academiccc. The
term Sleep may not really be so hyperbolical
as at first sight it seems, for the cessation of
the stimulus of light, and of the consequent
restrained position of the leaves, may be use-
ful to the vegetable constitution, as real sleep
is t© the animal. Another purpose is answered
by the nocturnal folding of some leaves, that
they shelter their flowers from the dew, the
advantage of which we shall explain hereafter.

Some pinnated leaves display a more ex-
traordinary sensibility, not merely to light,
but to the touch of any extraneous body,
or to any sudden concussion, as those of
Mimosa sensitive!, and pudica, Oralis sen-
sitive?, and Smithia sensitive?, Ait, HorL

ACTION OF LEAVES ON THE ATMOSPHERE. fill

Kezc\ v. 3, t. 13. An impression made even
in the most gentle manner, upon one of their
leaflets, is communicated in succession to all
of them, evincing an exquisite irritability,
for it is in vain to attempt any mechanical
solution of this phenomenon. One of this
tribe, Hetty mriim gyram, has a spontaneous
motion in its leaves, independent of any ex-
ternal stimulus, even of light, and only re-
quiring a very warm still atmosphere to be
performed in perfection. Each leaf is ter-
nate, and the small lateral leaflets are fre-
quently moving up and down, either equably
or by jerks, without any uniformity or co-
operation among themselves. It is difficult
to guess at the purpose which this singular
action is designed to answer to the plant it-
self ; its effect on a rational beholder can-
not be indifferent.

The chemical actions of light, heat, and
the component parts of the atmospheric air,
upon leaves, and, where the latter are want-
ing, on the green stems of plants, are now,
as far as concerns all plants in common, tole-
rably well understood. The observations and
experiments of Priestley and Ingenhousz have

£lf C8EMICAL ACTION OF

been confirmed, extended in a variety of
ways, or explained on the principles of im-
proved chemistry, by Dr„ Percival and Mr*
Henry in England, Dr. Woodhouse in Ame-
rica, and M. Sennebier and M. Theodore de
Saussure, as well as various other philoso-
phers, on the continent of Europe. It is
agreed that in the day-time plants imbibe
from the atmosphere carbonic acid gas,
(which was formerly called fixed air, and is
an union of oxygen and carbon), that they
decompose it, absorb the carbon as matter of
nourishment which is added to the sap, and
emit the oxygen. So they absorb the same
gas from water, when it is separated from
that fluid by the action of light. The burn-
ing of a candle, or the breathing of animals,
in confined air, produces so much of this gas,
that neither of these operations can go on
beyond a certain time, but the air so conta-
minated serves as food for vegetables, whose
leaves, assisted by light, soon restore the oxy-
gen, or, in other words, purify the air again.
This beautiful discovery, for the main prin-
ciples of which we are indebted to the cele-
brated Dr. Priestley, shows a mutual depend-

LEAVES ON THE ATMOSPHERE. 213

ance of the animal and vegetable kingdoms
on each other, which had never been sus-
pected before his time. Comparative expe-
riments upon the lower tribes of these king-
doms have not yet been made, but they
would probably afford us a new test for di-
stinguishing them. The air so copiously pu-
rified by a Conferva, one of the most inferior
in the scale of plants, may be very extensively
useful to the innumerable tribes of animated
beings which inhabit the same waters. The
abundant air-bubbles which have long ago
given even a botanical name to one supposed
species, Conferva bullosa, are probably a
source of life and health to whole nations of
aquatic insects, worms and polypes, whenever
the sun shines.

In the dark, plants give out carbon and
absorb oxygen : but the proportion of the
latter is small, compared to what they exhale
by day, as must likewise be the proportion
of carbon given out; else the quantity of
the latter added to their substance would be
but trifling, especially in those climates
where the proportion of day to night is nearly
equal, and which, notwithstanding, we know

2!4 CHEMICAL ACTION OF

to be excessively luxuriant in vegetation.
Plants also give out azotic gas : but M. de
Saussure is of opinion that this proceeds from
their internal substance ; and it appears by
his experiments to be rather a sign of disease
or approaching decay, than a regular che-
mical production of their constitution when
in health ; for Sennebier found the quantity
of oxygen emitted was in proportion to the
thickness of the leaf, or quantity of paren-
chyma. Yet the parenchyma must be in its-
original organized state, for when bruised ita
functions are destroyed.

Possibly such an alternation in the func-
tions of vegetables between day and night
may afford a necessary repose to their vital
principle, whose share in them we know to
be of primary importance. Whatever may
happen to plants in the dark, there can be
no doubt of their principal business in the
ceconomy of nature being what we have de-
scribed. The most luminous and compen-
dious view of the whole subject is given by
Dr. Thomson of Edinburgh in the fourth vol.
of his Chcmkimj, which is well worth the
attention of those who wish to enter mere

LEAVES ON THE ATMOSPHERE. 2i5

deeply into all the various chemical exami-
nations respecting it than suits our purpose.
It is only necessary to add a short view of
Dr. Darwin's hypothesis which Dr. Thomson
has not mentioned, probably on account of
its insufficiency. That lively writer thought
the watery perspiration of leaves, acted upon
by light, gave out oxygen for the use of the
plant itself, such oxygen being immediately
absorbed by the air-vessels. This is by no
means adequate to explain any of the phe-
nomena, but rather contradictory to most
of them, and is totally superseded by the ob-
servations and experiments of other writers.

There can be no question of the general
purpose answered to the vegetable constitu-
tion by these functions of their leaves. They
confirm Mr. Knight's theory of vegetation,
who has proved that very little alburnum or
new wood is secreted when light is kept from
the leaves. They also help us to understand
how essential oils mav be produced, which
are known, as well as sugar, to be composed
of oxygen, hydrogen and carbon in different
p oportions. We can now have a general
idea how the nutritious sap, acted upon by

216 CHEMICAL ACTION OP

all the agents above mentioned during its stay
in the cellular substance of the leaf, and
returned from thence impregnated with them
into the bark, may prove the source of increase,
and of peculiar secretions, in the vegetable
frame. That portion of sap sent to the flower
and fruit undergoes no less remarkable
changes, for purposes to which those curious
organs are devoted ; nor is it returned from
thence, as from the leaves, to answer any
further end. The existence of those organs
is still more temporary, and more absolutely
limited to their own purposes, than even that
of the leaves, from whose secretions theirs
are very distinct.

But when we attempt to consider how the
particular secretions of different species and
tribes of plants are formed ; how the same
soil, the same atmosphere, should in a leaf
of the vine or sorrel produce a wholesome
acid, and in that of a spurge or manchineel
a most virulent poison ; how sweet and nutri-
tious herbage should grow among the acrid
crowfoot and aconite, we find ourselves to-
tally unable to comprehend the existence of
such wonderful powers in so small and seem-

LEAVES ON THE ATMOSPHERE. £17

ingly simple an organ as the leaf of a plant.
The agency of the vital principle alone can
account for these wonders, though it cannot,
to our understanding, explain them. " The
thickest veil," says Dr. Thomson at the end
of his chapter on vegetation, " covers the
whole of these processes ; and so far have
philosophers hitherto been from removing
this veil, that they have not even been able
to approach it. All these operations, indeed,
are evidently chemical decompositions and
combinations ; but we neither know what
these decompositions and combinations are,
nor the instruments in which they take
place, nor the agents by which they are regu-
lated/'

The vain Buffon caused his own statue to
be inscribed " a genius equal to the majesty
of nature,* but a blade of grass was sufficient
to confound his pretensions,

sia

CHAPTER XVII.

Or THE SEVERAL KINDS OF FULCRA, OR
APPENDAGES TO A PLANT.

The word Fulcrum, whose proper mean^
ing is a prop or support, has been applied
by Linnaeus not only to those organs of
vegetables correctly so denominated, such
as tendrils, but also to various other appenr
dages to the herbage of a plant, none of
which are universal, or essential, nor is
there any one plant furnished with them
all. I prefer the English term Appendages
for these organs in general, to Props, because
the latter applies only to one of them. Seven
kinds of these are distinguished by Linnaeus,
nor do I find it necessary to enlarge that
number.

1. Stipula. The Stipula, a leafy appendage
to the proper leaves or to their footstalks,

OF THE FULCIU. $19

It is commonly situated at the base of the
latter, in pairs, and is extremely different
in shape in different plants.

The most natural and usual situation of
the Stipulas is in pairs, one stipula on each
side of the base of the footstalk, as in
Lathjrus latifolius, Engl Bot. t. 1108,
whose stipulas are half arrow-shaped ; also
in Willows, as Salix stipularis, t. 1214,
1 and S. anrita, t. 1487. In Rosa, Potcn-
tilla, and many genera allied to them, the
stipulas are united laterally to the foot-
stalk. See Potentilla alba, t. 1384. In
all these cases they are extrafoliace^ ex-
ternal with respect to the leaf or footstalk;
in others they are intrafoliacece, internal,
and are then generally simple, as those of
Polygonum, t. 1382, 756, &c. In a
laro-e natural order, called Rubiacece, these
internal stipulas in some cases embrace the
stem in an undivided tube above the inser-
tion of the footstalks, like those of Polif*
gonum just mentioned; in others, as the
Coffee, Coffea arabka, and the llamdlia
patens, Exot, Bot. t. 24, they are separate
Irnves between the footstalks, but meeting

220 OF THE FULCRA,

■just above their insertion. The Europaean
RubiacecB have whorled leaves, as Aspe-
rula, Galium, Rubia, Sec; but Asperula
cynanchica, Engl. Bot. t. 33, has some-
times two of its four leaves so small as to
look like stipulas, seeming to form an inter-
mediate link between such as have whorled
leaves and such as have opposite ones with
stipulas. The next step from Asperula is
Diodia, and then Spermacoce. In the
two last the bases of the stipulas and foot-
stalks are united into a common tube.

Some stipulas fall off almost as soon as

the leaves are expanded, which is the case

with the Tulip-tree,' Liriodendron tulipi-

fera ; in general they last as long as the

leaves.

The absence or presence of these organs,
though generally an indication that plants
belong to the same natural order and even
genus, is not invariably so. Some species
of Cistus have stipulas, others none, which
is nearly the case with grasses. The
stipula in this, one of the most distinct
of all natural orders, is peculiar, consisting
of an internal white membrane crowning

OH APPENDAGES OF PLANTS. 221

the sheath of their leaf, and clasping the
culm. See Phalaris canariensis, EngL
Bot. t. 1310, and La gurus ovatus, t. 1334.
In Aria carulea, t. 750, a few minute
hairs supply its place, while Sesleria cceru-
lea, t. 16 13, and some maritime grasses,
have scarcely more than the rudiment of
a stipula. Old writers call this organ in
grasses by a peculiar name ligitla^ and
others denominate it membrana foliorum,
but both terms are superfluous. A curious
instance of stipulas supplying the place of
leaves is observable in Lathyrus Aphaca,
t. II67, which has only one or two pair
of real leaves on the seedling plants, and
those soon disappear, serving chiefly to
prove, if any proof were wanted, that the
rest are true stipulas.

Remarkably scariose, or dry membra-
nous stipulas are seen in Illecebrum Paro-
nychia, FL Grcec. t 246, and in the genus
Pinus,

Bractea. The floral leaf, a leafy appen-
dage to the flower or its stalk. It is of a
riefcy of forms, and sometimes green.

922 OF THE FULCRA;

sometimes coloured. The Lime-trees,
T'tlia europcea, t. 610, and parvifolia^
f% 170.5, have a very peculiar oblong pale
floral leaf, attached to the flower-stalk.
The Lavenders, see Cart. Mag. t. 400
and 401, have coloured bracteas, and the
Purple-topped Clary, Salvia Horminum 9
FL Gnec. t. 20, exhibits a gradation from
the proper leaves to green bracteas, and
from them to coloured ones, which last
are barren, or unaccompanied by flowers.
Hence I am induced to believe this plant
a mere variety of S. viridis, t. 1 9> all whose
bracteas are green and fertile. Bartsia
alpina, Engl. Bot> t. 361, and Melam-
pyrum arvense, t. 53, display an elegant
transition from leaves to coloured bracteas.
The Orchis tribe have green leafy bracteas,
different in size in different species. A
most beautiful large and coloured bractea
is produced in Mussamda frondosa, Hort.
Mai. v. 2. t. 18, from one of the teeth of
the calyx, also in M. glabra of Willdenow,
and two new species brought from Ame-
rica by Mr. John Fraser. Spinous bracteas
of a curious construction guard the calyx

OR APPENDAGES OF PLANTS. 223

in A tract if lis cancellata. Linnseus observes
that no bracteas are to be found in the
class Tetradynamia.

The ochrea of Rottboll, Willdeno<rs
Principles of Botany, 50, which enfolds
the flower-stalks in Cyperus, see Engl
Hot. t. 1309, seems to me a species of
brae tea,

3\ Spina. A Thorn. This proceeds from
the wood itself, and is either terminal like
Hippophae rkamnoidss, Engl Bot. t. 425,
Rhammts catharticus, t. 1629 ; or lateral
as Crataegus (or Mespiius) Crus-galli,
tomentosa, parvifolia, &c.

Linnaeus observes that this sometimes
disappears by culture, as in the Pear-tree,
Pyrus sativa, which when wild has strong
thorns ; hence he denominates such culti-
vated plants tamed, or deprived of their
natural ferocity. Professor Willdenow,
Principles of Bot. 270, considers thorns as
abortive buds, and thence very ingeniously
and satisfactorily accounts for their disap-
pearance whenever the tree receives more
nourishment.

Q24 OP THE FULCRA,

The permanent footstalks of the Gum
Tragacanth shrub, Astragalus Traga-
cantha, are hardened into real spines, as
are the flowerstalks in Pisonia, as well
as the stipulas of Xanthium spinosum and
the Mimosa. — Linn. Mss.

4. Acidens, a Prickle, arises from the bark
only, and comes off with it, having no
connection with the wood, as in Rosa,
Rubus (the Bramble Raspberry, &c), and
Zizyphm, Willd. Sp. PL v. 1. 1102.

This is not liable to disappear by cul-
ture, being very distinct in nature from
the last.

Cirrus* A Tendril. This is indeed pro-
perly called a fulcrum or support, being
intended sole! y to sustain weak and climb-
ing stems upon more firm and sturdy ones.
By its means such climbers often reach,
in tropical forests, to the summits of lofty
trees, which they crown with adventitious
blossoms. Tendrils or claspers when young
are usually put forth in a straight direc-
tion; but they presently become spiral,

OR APPENDAGES OP PLANTS. 225

making several circumvolutions, by which
they take hold of any thing m their way,
and then assume a firmer texture. After
accomplishing a certain number of turns
in one direction, some tendrils have a
power of twining subsequently the contrary
way ; many of them moreover are branched
or compound, so that the chances of their
meeting with a support are multiplied.
The Vine, Vitis vinifcra, the various spe-
cies of Passion-flower, and the Pea or Vetch
tribe afford good examples of spiral ten-
drils. The Virginian Creeper Hedera, or,
as it ought to be called, Vitis, quinquefolia s
has branched tendrils, whose extremities
adhere to the smoothest flint, like the fibres
of Ivy. Gloriosa superba, Andr. Repos.
t. T29, and Flagellaria indica, have a
simple spiral tendril at the end of each
leaf; for they belong to the Monocoty-
ledones, the structure of whose whole her-
bage is generally of the most simple and
compendious kind. The flower-stalks of
Cardiospermum Halicacabum bear ten-
drils ; but a most singular kind of tendril
if it may so be called, which certainly has
Q

22(j OF THE FULCRA,

a right to the name of fulcrum, is found
in the Annona hexapetala, Linn. Suppl.
270. The flower-stalk of this tree forms a
hook, and grasps the neighbouring branch,
serving to suspend the fruit, which is very
heavy, resembling a bunch of grapes, and
indicates the plant in question to be either
a Michelia or an Uvaria.

6. Glandula, a Gland, is defined by Lin-
naeus as a little tumour discharging a fluid.
Such are abundant on the stalk and calyx
of a Moss Rose, Curt. Mag. t. 69, and
between the serratures of the leaf of Saliv
pentandra, Bay-leaved Willow; also on
the footstalks of Viburnum Opulus, Engl.
Bot. t. 33 c 2, and various species of Passion-
flower. The liquor discharged is in the first
mentioned instances resinous and fragran ,
in the latter a sort of honey.

7. Pilus. A Hair. This, according to the Lin-
mean definition, is an excretory duct of a
bristle-like form. Such it undoubtedly is it
the Nettle, Urtica, Engl Bot. t. 143, and
1. 1236, whose bristles are tubular and per-

OR APPENDAGES OF PLANTS. 227

vious, having each a bag of poison at its
base, like the fang of a serpent ; as well
as in numerous plants whose hairy coats
exude a viscid moisture. But the hairs
which clothe many plants are merely
a protection against cold, heat, or insects.
Sometimes they are hooked, sometimes
branched and entangled, as in Mullein,
Verbascum, t. 549, &c. InCroton, Solanum,
and Lavatera they have often a starry
figure. Very generally they are found,
under a microscope, to be curiously jointed.
Some Be<ro?ii<z bear on their leaves flat
little straps called by authors r amenta,
shaving's- instead of Cylindrical hairs ;
but I know not that they at all differ
in nature from the usual pubescence, nor
do they merit to be particularly distin-
guished. Some of the natural order of
asperifolicF, as Echium, t. 181, and Ly-
copsis, t. 938, especially some exotic spe-
cies of this order, are clothed with curious
white hard tubercles from which their
bristles proceed. Echiwnt pyrenaicum,
Desfont. Atlant. v. 1. 164, is an instance
of this.

q 2

228 OP THE FULCRA,

The pubescence of plants varies greatly
in degree according to differences of soil or
exposure ; several kinds, as Mentha hir-
suta, t. 447, 448, naturally hairy, being
occasionally found smooth, but if trans-
planted they soon resume their proper habit.
Yet the direction of the hairs or bristles
proves a very sure means of distinguishing
species, especially in the genus Mentha, the
hairs about whose calyx and flower-stalk
point differently in different species, and 1
have found it the only infallible distinction
between one Mint and another. See Trans,
of Linn* Soc. v* 5. 171. The accurate
Dr. Roth has lately applied the same test
to the species cf Myosotis, which all bota-
nists before him had either confounded
under M. scorpioides, Engl. Bot. t. 480,
or else separated upon vague principles.
Some species of Galium are admirably
characterized by the bristles of their leaves,
or of parts of their leaves, being hooked
backward or forward. We therefore ac-
ceptthe 272d maxim of Linnseus's Philoso-
phia Botanica with that limitation which
he himself has allowed in his commentary

OR APPENDAGES OF PLANTS. 229

upon it. " The Pubescence/' says he, " is
a ridiculous distinction, being for the most
part effaced by culture/' After quoting
examples, he concludes : " We are there-
fore not to have recourse to the hairiness
or spines of plants but in case of absolute
necessity/' Such necessity every botanist
will allow to have existed in the Mentha
and in Myosotis scorpioides ; and though
^he degree of pubescence varies from culture,
and even its structure be changeable, as
in Hedypnois hispida, Engl. Bot. t. 554,
and hirta, t. 555, its direction is I believe
as little liable to exception as any character
that vegetables present.

230

CHAPTER XVIII.

OF THE INFLORESCENCE, OR MODE OP
FLOWERING, AND ITS VARIOUS FORMS.

Inflorescence, inflorescentia, is used by
Linnaeus to express the particular manner in
which flowers are situated upon a plant, de-
nominated by preceding writers the modus
Jlorendi, or manner of flowering. Of this
the several kinds are distinguished as follows.

Verticillus. A Whorl. In this the flowers
surround the stem in a sort of ring; though
they may not perhaps be inserted on all
sides of it, but merely on two opposite
ones, as in Dead Nettle, Lamium, Engl.
Bot. t. 768—770, Mentha rubra, t. 1413,
and Clinopodium vulgare, t. 1401 ; or
even on one side only, as liumex mari-
timuSy t. 725. The flowers of Hippuris

OF THE INFLORESCENCE. 231

vulgaris, t. 703, are truly inserted in a
ring round the stem; but they are not
whorled independent of the leaves, and
are therefore more properly, with a re-
ference to the leaves, denominated axillary
and solitary.

Racemus, a Cluster, or Raceme, consists
of numerous rather distant flowers, each
on its own proper stalk, and all connected
by one common stalk, as a bunch of Cur-
rants, Ribes rubrum, Engl. Bot. t. 1289,
nigrum, t. 1291, and O rob us sylvutieus,
t. 518. A cluster is most generally droop-
ing or pendulous, and the flowers are all
expanded nearly at the same time.

A compound racemus occurs in Sola nam
Dulcamara, t. 565, and an aggregate one,
several being gathered together, in Actaa
racemom, DHL Elth. t. 67 ; but the ex-
ample of a bunch of Grapes, quoted by
Linnaeus for a racemus^ appears to me a
true thyrsus; see below.

Spica, a Spike, bears numerous flow
ranged along one common stalk, without

232 OF THE INFLORESCENCE.

any partial stalks, as in Satyrium hircinum,
Engl. Bot. t. 34, Orchis bifolia, t. 22,
Plantago major, t. 1558, and media,
t. 1559, Potamogeton heterophyllum,
t 1285, and fluitans, t. 1286; but this
is so seldom the case, that a little latitude
is allowed. Veronica spicata, t. 2, there-
fore, and Ribes spicatum, t. 1290, as well
as the Common Lavender, Lavandula
Spica, are sufficiently good examples of a
spike, though none of them has entirely
sessile flowers; and Linnaeus uses the term
in numerous instances where it is still less
correctly applicable. A spike generally
grows erect. Its mode of expansion is
much more progressive than that of the
raceme, so that a long period elapses be-
tween the fading of the lowest flowers and
the opening of the upper ones. The flowers
are commonly all crowded close together,
or if otherwise, they form separate groups,
perhaps whorls, when the spike is said to
be either interrupted, or whorled ; as in
some Mints. In Sanguisorba officinalis
the spike begins flowering at the top. See
Capihdum below.

OF THE INFLORESCENCE. 233

A compound spike is seen in Lavandula
pinnata, Curt. Mag. t. 401, and L. ab-
rotanoides of Willdenow.

Spica secunda, a spike whose flowers
lean all to one side, oecurs in Nardus
stricta, Engl. Bot. t. 290.

Spicula, a Spikelet, is applied exclusively
to grasses that have many florets in one
calyx, such florets, ranged on a little stalk,
, constituting the spikelet, which is there-
fore a part of the flower itself, and not
of the inflorescence; see Poa aquatica,
f-18-15, fluitans, t. 1520, Briza minor,
1. 1316, &c.

Corymb us, a Corymb, is a spike whose
partial flower-stalks are gradually longer
as they stand lower on the common stalk,
so that all the flowers are nearly on a level,
of which Spiraa opulifolia, a common
shrub in gardens, is an excellent speci-
men. The Linnaean class Tetr adynamia
exemplifies this less perfectly, as Car-
da mine prat en sis, Engl, Bot. t. 776,
Cheiranthus sinuatus, t. 46*2, and the com-
mon Cabbage, Brasska oleracea, t. b37,

£34 OF THE INFLORESCENCE,

in which the corijmbm of flowers becomes
a racemus of fruit, as happens also in that
section of the Veronicce, entitled by Lin-
nseus corymboso-raceniGS^E. The flowers of
Yarrow, Achillea, t. 757 and 753, and
several others of the compound class, as
well as the Mountain Ash, t. 337, grow
in a corymbose manner, though their in-
florescence may not come exactly under
the above definition. It is worthy of re-
mark that Linnaeus in that definition uses
the word spica, not racemus, nor has he
corrected it in his own copy of Phil. Pot.
p. 41, though he has properly altered a
slip of the pen in the same line, petiolis y
to pedunculis*. This shows he did not
restrain his idea of a spike absolutely to
sessile flowers, but admitted that extended
signification which nature justifies. Many
plants acquire partial stalks as the fruit
advances towards maturity.

* It might be expected from the numerous learned
editors and copiers of this and other works of Linnaeus,
that they should correct such manifest errors as the above
which any tyro might perceive.

OF THE INFLORESCENCE. 235

Fasciculus, a Fascicle, is applied to
flowers on little stalks, variously inserted
and subdivided, collected into a close bun-
dle, level at the top, as the Sweet William,
Dianihus barbatus, Curt. Mag. t. 207,
and D. Armeria, Engl. Bot. t. 31?.

Capitulum, a Head or Tuft, bears the
flowers sessile in a globular form, as St at ice

. Armeria , t. 226, Adoxa Moschateliina,
t. 453, and Gomphrena globosa, the Globe
Amaranthus of the gardens.

Perhaps the inflorescence of Sanguisorba
officinalis, t. 1312, might be esteemed a
capitulum, because its upper flowers come
first to perfection, as in Adoxa, which
seems contrary to the nature of a spike ;
but it does not appear that all capitate
flowers expand in the same way, and San-
guisorba canadensis has a real spike, flow-
ering in the usual manner, from the bottom
upwards. So Allium descendant Curt.
Mag. t. 251, opens its upper, or central,
flowers first, contrary to the usual order in
its genus; both which instances prove such
a diversity to be of small moment.

236 OF THE INFLORESCENCE.

Umbella, an Umbel, for which some au-
thors retain the obsolete old English name
of Rundle. In this several flower-stalks, or
rays, nearly equal in length, spread from
one common centre, their summits forming
a level, convex,, or even globose surface,
more rarely a concave one. When each
ray is simple and single-flowered, it is called
a simple umbel, as those of Allium ursi-
num, Engl Bot. t. 122, Ivy, t. 1267,
Primula veris, t. 5, farinosa, t. 6, ela-
tior 9 t. 513, and Eucalyptus resinifer,
Exot. Bot. t. 84. In a compound umbel
each ray or stalk mostly bears an umbel-
lula, or partial umbel, as Athamanta
Libanotis, Engl. Bot. t. 138. This is
usually the case in the very natural order
of plants called umbelliferous, to which
the last-mentioned, as well as the common
Carrot, Parsnep, Parsley, Hemlock, &c.
belongs.

A few only of this order have simple urn*
bels, as Hydrocotyle vulgaris, t. 751, and
the curious Astrantia and Eriocalue, Exot.
Bot. t. 76 — 79. In Euphorbia the umbel
is differently compounded, consisting of

OF THE INFLORESCENCE, 237

3, 4, 5 or numerous rays, each of which
is repeatedly subdivided, either in a three-
fold or forked manner. See Engl* Hot.
t. 883, 959, &c.

Cyma, a Cyme, has the general appear-
ance of an umbel, and agrees with it so far
that its common stalks all spring from one
centre, but differs in having those stalks
variously and alternately subdivided. Ex-
amples are found in Viburnum, Engl. Bot.
t. 331, 332, and the common Laurusti-
nus, as also in Sambucas, Elder, t. 475,
476, This mode of inflorescence agrees
with a corymbus also in general aspect, but
in the latter the primary stalks have no
common centre, though the partial ones
may sometimes be umbellate, which last
case is precisely the reverse of a cyma.

Panic ula, a Panicle, bears the flowers
in a sort of loose subdivided bunch or
cluster, without any order. When the
stalks are distant, it is called diffusa, a
lax or spreading panicle, as in Saxijraga
umbrosa, t. 663, so frequent in gardens
under the name of London Pride, and

238 OF THE INFLORESCENCE.

S. Geum, £.1561, but particularly in many
grasses, as the common cultivated Oat, and
Avena strigosa, t. 1266 ; in this tribe the
branches of the panicle are mostly semi-
verticillate ; see Air a aquatica, t. 1557.
A divaricated panicle is still more spread-
ing, like those of Prenantkes muralis,
t. 4*57, and Spergula arvensis, t. 1535 ;
the last being dichotomous or forked. A
dense or crowded panicle, coarctata, is
observable in Milium lendigerum, t. 1107?
and Agrostis stolonifera, t. 1532, but still
more remarkably in Phleum paniculatum,
t. 1077, whose inflorescence looks, at first
sight, like a cylindrical spike, but when
bent to either side, it separates into
branched lobes, constituting a real pa-
nicle.

Thyrsus, a Bunch, is a dense or close
panicle, more or less of an ovate figure, of
which the Lilac, Syringa vulgaris, Curt.
Mag. t. 183, Tussilago hybrida and
Petasites, Engl Bot. t. 430, 431, are
examples cited by Linnaeus. I presume
likewise to consider a bunch of grapes.

OF THE INFLORESCENCE. 239

Fitis vinifera, as a true thyrsus, to the
characters and appearance of which it cor-
rectly answers. Its ultimate terminations
are sometimes obscurely umbellate, espe-
cially while in blossom, which is no ob-
jection here, but can never be the case in
a racemus, whether simple or compound.
See Racemus.

Of simple flower-stalks, whether solitary
or clustered, radical or cauline, axillary,
lateral or terminal, we have already spoken.

Linnaeus remarks that the most elegant

O

specific characters are taken from the in-
florescence. Thus the Apple, Engl. Bot.
t. 179? ftnd the Pear, form two species of
Pyrus, so far at least a most natural genus,
the former of which bears an umbel, the
latter a corymb. Pyrola uniflora, t. 14(5,
secunda, t. 517, and umbellata, Curt. Mag.
t. 778, are-admirably distinguished by their
several forms of inflorescence.

240

CHAPTER XIX.

OF THE FLOWER AND FRUIT,

Having examined the general structure
and external form of plants, we now come to
more important and even essential, though
more transitory organs — the flower and fruit*
or parts of fructification. By these each
species is perpetually renewed without limits,
so far at least as the observation of mankind
has reached ; while, as we have already men-
tioned, all other modes of propagation are
but the extension of an individual, and sooner
or later terminate in its total extinction.

Nothing can be more happy than the Lin-
nsean definition of these organs ; Phil. Bot.52.
" The fructification is a temporary part of
vegetables, destined for the reproduction of
the species, terminating the old indivdiual
and beginning the new/'

OF THE FLOWER AND FRUIT. 241

Pliny had long ago beautifully said that
'* blossoms are the joy of trees, in bearing
which they assume a new aspect, vyeing
with each other in the luxuriance and va-
riety of their colours." Linriseas has justly
applied this to plants in general, and, im-
proving upon the idea, he considers their
herbage as only a mask or clothing, by no
means indicative of their true nature or cha-
racter, which can be learned from the flower
and fruit alone.

Mr. Knight has traced his central vessels,
by which the sap is conveyed from the root,
into the flower and fruit. On the returning
sap in the bark of these parts he has not been
able to make any distinct observation ; but
he has determined that no matter of increase
is furnished from the flowers or their stalks,
as from leaves, to the part of the branch be-
low them, nor indeed to any other part, T?hiL
Trans. for 1801,^.340. There can be nodoubt
that certain parts of the flower, which we shall
presently describe, perform functions respect-
ing air and light analogous to those of leaves,
but entirely subservient to the benefit of the
flower and fruit. Their secretions, formed

It

OF THE PARTS

from the returning sap, are confined to their
own purposes. As soon as these are accom-
plished, a decided separation of vessels takes
place, and the ripe fruit, accompanied per-
haps by its stalk, falls from the tree. Dr.
Hales tried in vain to give any flavour to
fruit by the most penetrating and volatile
fluids conveyed through the sap- vessels ; for
the laws of secretion are absolute in the or-
gans of the flower, and their various results
are, if possible, more strikingly distinct than
even those we have contemplated in the leaves.
It is scarcely necessary to repeat that the
fructification is essential to vegetables. A
plant may be destitute of stem, leaves, or
even roots, because, if one of these parts be
wanting, the others may perform its func-
tions, but it can never be destitute of those
organs by which its species is propagated.
Hence, though many individual plants may
be long without blossoms, there are none, so
far as nature has been thoroughly investi-
gated, that are not capable, in favourable
circumstances, of producing them, as well as
seeds; to whose perfection the blossoms them-
selves are altogether subservient.

OP FRUCTIFICATION. 243

Linnceus distinguishes seven parts of fruc-
tification, some of which are essential to the
very nature of a flower or fruit, others not
so indispensably necessary, and therefore not
universal.

L Calyx, the Calyx or Flower-cup, generally
resembling the leaves in texture and co-
lor?, and forming the outermost part of a
flower. This is not essential, and is often
absent.

II. Corolla, the Corolla, or more delicate
coloured internal leaf or leaves, properly
petals, of a flower, likewise not essential.

III. Stamen, or Stamina, the Stamen or
Stamens, commonly of a slender or thread-
like form, bearing some kind of knob or
cellular body, and ranged internally with
respect to the Corolla. These are es-
sential.

IV. Pistillum, or Pistilla, the Pistil, or Pistils,
in the centre of the flower, consisting of
the rudiments of the fruit, with one or

r 2

244 DIFFERENT KINDS OF CALYX.

more organs attached to them, and, of
course, essential.

. PericGrpium, the Seed-vessel, of a pulpy,
woody, or leathery texture, enclosing the
seeds, but wanting in many plants.

VI. Semen, the Seed, the perfecting of which
is the sole end of all the other parts.

VII. Receptacuhnn, the Receptacle, basis or
point of connection. This must necessa-
rily be present in some form or other.

I. Calyx. The Flower-cup, or more cor-
rectly the external covering of the flower,
when present, was originally divided by
Linmeus into seven kinds, some of which
are more justly so denominated than the
others, and I have ventured to make an
alteration in his list.

1. Perianthium. Calyx, properly and com-
monly so called, when it is contiguous to
and makes a part of the flower, as the five
green leaves which encompass a Rose, in-

DIFFERENT KINDS OF CALYX,. 245

eluding their urn-shaped base; the two-
oreen bristly ones which enfold the bud %
in Glauclum Ititeum, Fl. Brit. Engl Bot.
t. 8 ; the tubular part, comprehending the
scales at its base, in the Pinks, t. 61, 62,
or the globular scaly cup in Centaurea,
t. 56. The Tulip, t. 63, is a naked flower,
having no calyx at all.

This part is of an infinite variety of
forms in different genera, being either
simple or compound, divided or undivided,
regular or irregular. In some instances it
is permanent till the fruit is ripe, in others
it falls even before the flower is well ex-
panded.

Some genera have a double perianthium,
as Malva, t. 67 1, or even a triple one, as
Scabiosa, t. 1311.

I. Itwolucrum. Involucre of Professor Mar-
tyn ; but I generally retain the Latin ter-
mination. This is remote from the flower,
and can scarcely be distinguished clearly
from a Br acted. The term was first
adopted by Linnaeus, at the suggestion of
his friend Artedi, in order to distinguish
8

246 OF THE INVOLUCRUM,

the genera of umbelliferous plants, for
which purpose the latter deemed the part
jn question very important. But accord-
ing: to the laws which Linnaeus had laid
down, the parts of the flower and fruit
alone were to afford generic characters,
and the most sound botanists have ever
since kept to this rule, with infinite advan-
tage over less correct ones, however ready
to derive ideas respecting the natural habjt,
and secondary characters, of a genus, not
only from the inflorescence and bracteas,
but even from the leaves, stipulas, or other
parts. Linnaeus and Artedi, therefore, were
obliged to consider the involucra and invo-
lucella, the former accompanying the ge-
neral and the latter the partial umbels, as
a sort of calyx, and the umbel altogether as
one aggregate flower, composed of florets
united by a common radiated receptacle.
Consequently a cyme must be considered
in the same light; nor are reasons wanting
in support of this hypothesis, which we
shall consider after having first explained
all the parts of fructification.

In Euphorbia, however, the term bractea

OF THE IN VO LUCRU M . 347

would surely be more proper -than involu-
vrum or involucellum, as is evident from
a consideration of the inflorescence of the
whole genus, so very different in different
species. In £, Pep lis, and many others,
the flowers are solitary and axillary; in
others again, as E. amygdaloides, Engl
Bot. t. 256, and Characias, t. 442, some
flower-stalks are umbellate, some scattered;
and the subdivisions of the umbel in all
are ultimately forked, that is, of a nature
between umbellate and scattered. Th?s
genus has, moreover, a proper calyx or
periantlrium of a most distinct and pecu-
liar nature. Some species of Anemone, a
genus destitute of a pcrianthium, are said
by Linnaeus to have an involucrum, as
A. Pulsatilla, t. .51, for which the name
of bractea would be vastly more correct,
though in A. Hepatica, Curt. Mag. t. 10,
it is placed so near the flower as to seem a
part of it, which* however, is really not the
case.

The name of Involucrum is applied by
Gleditsch to the membrane covering the
fructification of ferns; nor have I, in study-

248 OF THE AMENTUM.

ing this part with peculiar attention in
order to reform the genera of these plants,
see Tracts relating to Js atural Hihtory,
p. 215, found reason to contrive any new
appellation. My learned friends Willde-
now and Swartz have judged otherwise,
calling this membrane the intiusiuw, or
coverinp'; which seems to me altogether
superfluous. See its various forms in Engl.
Bot. t. 1458—60, 1150, 1159, 1160, &c.

3. Amentum. Catkin, denominated by au-
thors before Linnaeus julus, nucamentum,
or catulus ; consists of a common recep-
tacle of a cylindrical form beset with nu-
merous scales, each of which is accom-
panied by one or more stamens or pistils,
so that the whole forms an aggregate
flower. The receptacle itself and the bases
of the scales are firmly united, and the
whole catkin fails off entire, except that
in some instances the upper part of each
scale withers away, as in the Willow genus,
SalLr, Eng. Bot. t. 1388—90, 1402—4,
&G. 5 the seed-vessels in that genus being
quite distinct from the scales. In others,

OF THE AMENTUM! 249

the whole scale remains, enlarges, hardens,
and protects the seed, as in Tinus, the Fir
tribe. Such is the case with catkins of
fertile flowers, which are necessarily per-
manent till the seed is ripe ; barren ones
fall as soon as the stamens have performed
their office. Every catkin consists gene-
rally of either one kind of flower or the
other. There are few certain and invari-
able instances of stamens and pistils in
the same catkin, that circumstance oc-
curring chiefly in a few species of Salix

and Carex; nor is Typ'ha, t. 1455 — 7,
an exception to this. Examples of barren-
flowered catkins are seen, not only in Salix
and Piniis, but in several plants whose
fertile or fruit-bearing flowers are not cat-
kins, such as the Walnut, and, unless I am
much mistaken, the Hasel-nut, t. 723.
Each nut or seed of the latter has a per-
manent coriaceous calyx of its own, inad-
vertently called by Gaertner an involucntm,
though he considers the whole as an amen-
turn, which this very calyx proves it not
to be*. Hamulus, the Hop, t. 427, has a
catkin for the fertile {lower only.
* It appears moreover that Carpinus, the Hornbeam,

Q5G OF THE GLUME*

4. Spatha. Sheath, a covering which bursts
longitudinally, and is more or less remote
from the flower. This is exemplified in
the Snow-drop, Galanthus nivalis, t. 167,
the various species of Narcissus, t. \1, 275

j and 276, and the Arum, t. 1298. The
Spatha of the latter encloses a Spadix, or
elongated receptacle, common to many

. flowers, according to the genuine Linnaean,
idea of this kind of calyx, taken from Palm-

. trees, In these the Spadix is branched,

5. Gluma. Husk, the peculiar calyx of
Grasses and Grass-like plants, of a chaffy
texture. These husks are usually com-
pressed, embracing each other at the base,
as in Phleum pratense, t. IO76. Some-
times they are depressed, flattened verti-
cally, as in Briza, t. 540 and 1316. To
the husk belongs the Arista, Beard or
Awn, a bristle-shaped appendage, usually
spiral, and possessing the property of an
hygrometer. This, how r ever, is not always

has hitherto erroneously been supposed to have an amen-
tum for the fertile flower. The true nature of the cover-
ing of the seed, as well as of the common stalk, proves
it otherwise.

AND TERICHjETIUM. 251

present, even in different individuals of
the same species.

* ( Unfortunately for the science^
On the awn there 's no reliance."

So says, or rather sings, with more truth
than sublimity, the ingenious author of
the Flora Londinensis ; fuse. 6, t. 8.

The spiral kind of awn is most fre-
quently attached to the Corolla of grasses,
which is precisely of the same husky na-
ture as their calyx, and is, by some bota-
nists, considered as such. Specimens of
glumce mutie&i beardless husks, are seen
mPhalariscanariaisis, Engl. Hot. t. 1310,
and glumce arista tee, awned ones, in La-
gurus ovatus, t. 1334, and Stipa ' pe?inata,
t. 1356.

Perichcetium. A scaly sheath, investing
the fertile flower, and consequently the base
of the fruit-stalk, in some Mosses. In the
genus Hypnum it is of great consequence,
not only by its presence, constituting a part
of the generic character, but by its dif-
ferences in shape 3 proportion, and struc-

OF THE P'ERICHATIUM

ture, serving frequently to discriminate
species. See Engl Hot. U 1037—9, 1182,
1445 — 8, &c. ; see also the same part in
Neekera, t. 1443, 4. Linnaeus apears by
his manuscripts to have intended adding
this to the different kinds of calyx, though
it is not one of the seven enumerated in
his printed works. Nor is he, surely, cor-
rect in allowing it to the genus Junger-
mannia. The membranous part which he
there calls pcrichcetium is strictly analo-
gous indeed to the cah/ptra or veil of real
mosses, esteemed by him a kind of calyx ;
but as I presume with Schreber to reckon it
rather a corolla, and Hedwig once thought
the same, and as Jungermannia has more
or less of a real calyx besides, see EngL
Hot. t. 771? &c, I would no longer apply
the term perich&tium to this genus at all.

The part called calyptra being removed
from the list, as being a corolla, the peri-
. chcctiiim takes its place among the seven
kinds of calyx. We lay less stress upon
this coincidence than Linnaeus might have
done, when, according to the fashion of
the times, he condescended to distribute

AND VOLVA. 253

his immortal Philosophia Botanica into
12 chapters and 365 sections, and reckoned
seven parts of fructification as well as seven
species of calyx.

7- Volva. Wrapper, or covering of the Fun-
gus tribe, of a membranous texture, con-
cealing their parts of fructification, and in
due time bursting all round, forming a
'ring upon the stalk, as in A gar km pro-
cerus, Sozcerb. Fung. t. 190, and A. cam-
pestris, the Common Mushroom, t. 305.;
Such at least is the original meaning of
this term, as explained in the Phil. Bot.\
but it has become more generally used,
even by Linnaeus himself, for the more
fleshy external covering of some other
Fungi, which is scarcely raised out of the
ground, and enfolds the whole plant when
young. SeeAgaricus volvaceus, t. 1, and
Ly coper don fornicatum, £.198; also the
very curious L. phalloides, t. 390, now
made a distinct genus by the learned Per-
soon, under the name of Batarrea pltal-
loidrs.

^54 ORIGIN OF THE CALYX.

Linnaeus adopted from Caesalpinus the opi-
nion that the Calyx proceeded from the bark,
like 1 the leaves, because of its similarity in
colour and texture to those organs. He even
refined upon the original idea, and supposed
this part to proceed from the outer bark, while
the more delicate corolla originated in the
liber. What is now known of the physiology
of the bark, as explained in several of our
preceding chapters, renders this hypothesis
totally inadmissible.

The knowledge of the real use of leaves,
see chapter 16, may however throw some light
upon that of the calyx. Besides protection
of the flower from external injuries, which is
one evident use of this part, it appears highly
probable that it may often contribute to the
growth and strength of the stalk which sup-
ports it, as the leaves do to that portion of
branch below them. The stalk often swells
considerably during the growth of the flower,
especially just below the calyx, becoming
more woody, an alteration frequently neces-
sary for the support of the ripening fruit-
When the calyx falls very early, as in the

0£ THE COKOLLA, 25$

Poppy tribe, Papaver and Glaucium,.! can-
not find that the flower-stalk is subsequently
enlarged, nor in any manner altered ; while
in genera without number, whose calyx is
permanent, the stalk becomes not only more
woody, but often considerably thickened.

II. Corolla. The Corolla, vulgarly called
the leaves of the flower, consists of those
1 more delicate and dilated, generally more
coloured leaves, which are always internal
with respect to the calyx, and constitute
the chief beauty of a flower. In the Rose
the Corolla is red and fragrant ; in the
Violet purple ; in the Primrose yellow.

This term includes two parts, the Petal,
Petalum, and the Nectary, Neciarium.
The former is either simple, as in the Prim-,
rose, in which case the Corolla is said to
be monopetalous, of one petal ; or com-
pound, as in the Rose, in which it is poly-
petalous, of several. The Nectary is some-
times a part of the petal, sometimes sepa-
rate from it.

A monopetalous Corolla consists of two
parts; the tube, tubus, the cylindrical part

256 FORMS OF THE COROLLA,

enclosed in the calyx of the Primrose ; and
the limb, limhus, which is the horizontal
spreading portion of the same flower. The
analogous parts of a polypetalous Corolla,
as in the Wall-flower or Stock, are named
the claw* unguis, and the border, lamina.

The Corolla is infinitely diversified in
form in different genera, whence Tourne-
fort and Rivinus derived their methods of
arrangement. It is called regular when
its general figure is uniform, as in the Rose,
the Pink, the Columbine, Aquilegia vul-
garis, Engl. Bot. t. 297, and Gentian a
Pneiwwnanthe, t. 20 ; irregular when
otherwise, as the Violet, t. 619, 620,
Dead-nettle, t. ?6S, and Laihyrus, t. 805
and 1108. An equal Corolla is not only
regular, but all its divisions are of one
size, like those of the Primrose, t. 5, Cam-
panula, t. 12, or Sazifraga, t. 9 ; an un-
equal one is when some segments are alter-
nately smaller than the others, as in Bu-
tojnns, t. 651, or otherwise different, as in
Aquilegia, t. 297* It is by no means al-
ways necessary, in defining characters of
genera, to use these last terms, it being

FORMS OF THE COROLLA. 257

sufficient in general to say that a Corolla
is regular in opposition to one that is irre-
gular ; more especially as some species of a
genus may possibly have an equal corolla,
others an unequal one.

The most usual shapes of a monopetalous
corolla are

campanulata, bell-shaped, as in Campa-
nula , t. 12.
4r$undibulifqrmts? funnel-shaped, Pulmo-

naria, t. 118.
hypocrateriformis, salver-shaped, Primula,

t.4.
rotata, wheel-shaped, that is, salver-shaped

with scarcely any tube, Borago, t. 36.
ringens, ringent, irregular and gaping like
the mouth of an animal, Lamium, t. 768;
called by former botanists labiata, lip-
ped.
personata, personate, irregular and closed
by a kind of palate, Antirrhinum, t. 129-
Those of a polypetalous one are
cruciformis, cruciform, regular and like
a cross, Dent aria, t. 309, and Cheiran-
thus, t. 462.
rosacea, rosaceous, spreading like a rose.
Dry as, t. 451.

s

258 PHYSIOLOGY OF

papilionacea, papilionaceous, irregular and
spreading, somewhat like a butterfly,
Lathy rus, t. 1108. The various petals
which compose such a flower are di-
stinguished by appropriate names, as
vexillum, standard, the large one at the
back ; al<£ 9 wings, the two side petals ;
and carina, the keel, consisting of two
petals, united or separate, embracing
the internal organs. In Trifolium all
the petals are sometimes united into one
at the lower part.

incompleta, incomplete, when parts, which
analogy would lead us to expect, are
deficient, as in Amorpha, a papilionace-
ous flower apparently, but consisting of
the vea ilium only ; or Hitter a of Schre-
ber, a rosaceous one with a single la-
teral petal, seeming as if four others had
been stripped off.

It is remarkable that irregular flowers
sometimes vary to regular ones in the
very same plant, as in Bignonia radi-
cans, Curt. Mag. t. 485; and Antir-
rhinum Linaria, Engl. Bot. t. 658 and
260.

Linnaeus was of opinion that the Corolla

THE COROLLA. 239

originated from the Liber or inner bark, as
the Calyx from the outer, but this cannot be
defended now the real physiology of the bark
is better understood.

The whole use and physiology of the Co-
rolla have not yet been fully explained. As
a protection to the tender and important parts
within, especially from wet, its use in many
cases is obvious, but by no means in all.
Linnaeus imagined it to serve as wings, to
waft the flower up and down in the air, and
so to promote the functions of the Stamens
and Pistils, as will hereafter be described;
nor is this opinion unfounded.

Sprengel has ingeniously demonstrated, in
some hundreds of instances, how the Corolla
serves as an attraction to insects, indicating
by various marks, sometimes perhaps by its
scent, where they may find honey, and ac-
commodating them with a convenient resting-
place or shelter while they extract it. This
elegant and ingenious theory receives con-
firmation from almost every flower we exa-
mine. Proud man is disposed to think that

" Full many a flower is born to blush unseen/'
because he has not deigned to explore it ;

260 PHYSIOLOGY OF

but we find that even the beauties of the
most sequestered wilderness are not made in
vain. They have myriads of admirers, at-
tracted by their charms, and rewarded with
their treasures, which very treasures would
be as useless as the gold of a miser to the
plant itself, were they not thus the means of
bringing insects about it. The services ren-
dered by such visitants will be understood
when we have described all the parts of a
flower.

Besides the above purposes, I have always .
conceived the Corolla to fulfil some important
ofiice to the essential parts of the flower with
respect to air, and especially light. It not
only presents itself in a remarkable manner
to the sun-beams, frequently closing or droop-
ing when they are withdrawn, but it is so
peculiarly distinguished by beauty or brilli-
ancy of colour, that one cannot but think its
functions somewhat different from those of
the leaves, even with regard to light itself.
pr. Darwin calls the Corolla the lungs of
the stamens and pistils, and with great pro*
bability, for they abound in air-vessels. But
when we consider the elaborate and peculiar

THE COROLLA. 261

secretions of a flower, the elastic and inflam-
mable pollen , the honey, and the exquisite! y
volatile perfume, as we know from the curi-
ous discoveries of modern chemistry how great
a share light has in the production of such,
we cannot but conclude that the petals must
be of primary importance with respect to their
secretion by its means.

Sometimes the Corolla is very short-lived ;
sometimes very lasting, even till the fruit is
perfected, though mostly in a faded condi-
tion. In double flowers I have observed it
to be much more durable than in single ones
of the same species, as Anemones and Pop-
pies, because, as I conceive, of its not having
performed its natural functions, the stamens
and pistils of such flowers being obliterated,
or changed to petals ; hence the vital prin-
ciple of their corolla is not so soon exhausted
as usual. Phil. Trans, for 17b'8, p. l6o.

The Corolla, as already observed, is not
essential. Whatever its functions may be,
the) r can be occasionally performed by the
Ca^lyx perhaps, or even by the Filaments of
the Stamens ; as those of leaves are, in leaf-
less plants, by the stems. When a flower

262 DISTINCTIONS BETWEEN

has only one covering, it is not always easy
to say whether that be a Calyx or Corolla.
When green and coarse in texture like the
former, we call it so, as in Chenop odium,
Engl. Bot. t. 1033, and 1721—4, and the
natural relationship of this genus to Folygo-
num, t 1044, 989, 756, &c, leads us to
reckon the same part in the latter a coloured
calyx. On the other hand, when the part
present is delicate and finely coloured, like
the generality of Corollas, we denominate it
such ; more especially if the plant to which
it belongs be allied to others that have a
Calyx besides, as in Tulipa, t. 63, allied to
Leucojum, t. 621, which has a Spatha. The
great Jussieu denominates this part in the
Tulip and other liliaceous plants, however
beautiful, a Calyx. His definition of a Corolla
is " that covering of a flower which is in-
vested with the calyx, being very rarely
naked; a continuation of the inner bark of
the flower-stalk, not of its cuticle ; not per-
manent, but mostly falling off with the sta-
mens ; surrounding or crowning the fruit,
but never growing united with it ; and having
its parts or segments for the most part alter-

COROLLA AND CALYX. 263

nate with the stamens, which are equal to
them in number/' By this rule the tube and
six segments of a Narcissus, L 17, 275 and
27 6 y constitute the Calyx, and then surely
what Jussieu calls a Crown, and Linnaeus a
Nectary, must be allowed the name of Co-
rolla. On the other hand, the Spat ha be-
comes a Bractea. Consequently the whole
order of Liliaceous flowers in general have a
coloured Calyx only, which seems hardly
admissible ; and yet I cannot conceal a re-
cent discovery which strongly confirms the
opinion of my acute and candid friend. Two
species of a new genus, found by Mr. Menzies
on the West coast of North America, have
beautiful liliaceous flowers like z\nAgapa?}thi(s>
with six internal petals besides ! I must how-
ever protest against the idea of the Corolla
originating exclusively from the inner bark,
as well as of the cuticle not beins; continued
over it, for reasons sufficiently apparent frcm
the former part of this work.

It is a Linngean rule that the Stamens
should be opposite to the segments of the
Calyx, and alternate with the parts of the
Corolla, Its author nevertheless seems of

264 DISTINCTIONS BETWEEN

opinion that no absolute means of distinction
between these two parts can be pointed out,
except colour ; of the insufficiency of which
he is aware. If however the Corolla performs
functions with respect to light which the Calyx
does not, and those functions are indicated
by its colour, a distinction founded on such
a principle is both correct and philosophical.
We must then conclude that in most liliaceous
plants, not in att 9 the two organs are united
into one, and indeed the outside is often
green and coarse like a Calyx, the inner co-
loured and delicate ; witness Ornithogalum,
i. 21, 130 and 499, Narthechim, t. 535, &c.
Linnaeus has the same idea respecting D^ h ne,
t. 119 and 1381, and the analogy is con-
firmed by Giiidia, which is a Daphne with
petals. In Trollius, t. 28, and Helleborus,
t. 200 and 6 13, Linnaeus considers as petals
what Jussieu, following Vaillant, thinks a
Calyx. Of these plants we shall soon have
occasion to speak again.

I cannot but consider as a sort of Corolla
the Calyptra or Veil of Mosses, which Lin-
naeus reckoned a Calyx. Schreber, very
deep and critical in his inquiries concerning

COROLLA AND CALYX. 265

these plants, and Hedwig, so famous for his
discoveries among them, were both of this
opinion, though the latter seems to have re-
linquished it. The organ in question is a
membranous hood, covering the unripe fruit
of these diminutive vegetables, like an ex-
tinguisher ; but soon torn from its base, and
elevated along with the ripening capsule.
See Engl. Bot. t. 558, &c. The great pe-
culiarity of this part, whatever it be called,
consists in its summit performing the office of
a stigma, as Hedwig first remarked. In
Jangermannia, t. 77 1> &c, the very same
part, differing only in usually bursting at the
top to let the fruit pass, is named by Lin-
naeus a perichcetiam, but very incorrectly,
as we have already hinted.

Whatever office the Petals may perform
with respect to air and light, it is probable that
the oblong summit of the Spadix in Arum,
t. 1/298, answers the same purpose. When
this part has been for a short time exposed
to the light, it assumes a purplish brown
hue, which M. Senebier seems to attribute-
to the same cause which he thinks produces
the great heat observed in this Bower, the

266 OF THE NECTARY

rapid combination of oxygen gas with the
carbon of the plant; an hypothesis hardly
adequate to explain either.

Nectarium, the Nectary, may be defined
as that part of the Corolla which contains or
which secretes honey. It is perhaps in effect
nearly universal, as hardly a flower can be
found that has not more or less honey, though
that liquor is far from being universally, or
even generally, formed by any apparatus
separate from the Petals. In monopetalous
flowers, as Lamium album the Dead Nettle,
t. 768, the tube of the corolla contains, and
probably secretes, the honey, without any
evident Nectary. Sometimes the part under
consideration is a production or elongation of
the Corolla, as in Violets ; sometimes indeed
of the Calyx, as in the Garden Nasturtium,
Tropceolum, Curt. Mag. t. 23 and 98, whose
coloured Calyx partakes much of the nature
of the petals. Sometimes it is distinct from
both, either resembling the petals, as in Aqui*
legia, Engl Bot. t. 297, or more different,
as in Epimedium, t. 438, Helleborus 9 t. 200
and 613, Aconitum, the Common Monkshood,
arid Delphinium^ the Larkspur. Such at

AND HONET. 267

least is the mode in which Linnaeus and his
followers understand the four last-mentioned
flowers ; but we have already hinted that
Jussieu is of a different opinion, and he even
calls the decided Nectary of Epimedium an
internal petal! Difficulties attend both the-
ories. It seems paradoxical to call petals those
singular bodies in Aconitum, like a pair of
little birds, which are manifestly formed only
to hold the honey, and not situated nor con-
structed so as to perform the proper functions
of petals; but on the other hand Ranunculus,
1. 100, 515 and 51 6, one of the same natural
order, has evident calyx and petals, which
latter have a honey-bearing pore in their
claw, evincing their identity with the less
petal-like Nectaries just described. Other
instances indeed of Nectaries in the claws of
petals are found in the Crown Imperial and
Lily ; which only confirms more strongly the
compendious construction of the Lily tribe,
the leaves of their flowers in these examples
being Calyx, Petals and Nectaries all in
one.

The most indubitable of all Nectaries, as
actually secreting honey, are those of a

268 OF THE NECTARY

glandular kind. In the natural order of
Cruciform plants, composing the Linnaean
class Tetradynamia, these are generally four
green glands at the base of the Stamens. See
Dentaria, Engl. Bot. t. 309, Sisymbrium,
t. 525, and Brassica, t. 637- In Salix,
t. 1488, and Geranium, t. 322, 75, Sec.,.
similar glands are observable; whilst in
Pelargonium, the African Geranium, the
Nectary is a tube running down one side of
the flower-stalk.

The elegant Parnassia, t. 82, of which we
are now acquainted with two new American
species, has a most elaborate apparatus called
by Linnaeus Nectaries, but which the cau-
tious Jussieu names Scales only. Linnaeus
usually called every supernumerary part of a
flower Nectary, from analogy only, though
he might not in every case be able to prove
that such parts produced honey. This is
convenient enough for botanical distinctions,
though perhaps not always right in physio-
logy ; yet there is nothing for which he has
been more severely and contemptuouslv cen-
sured. He was too wise to answer illiberal
criticism, or he might have required his ad-

AND HONEY. 269

versaries to prove that such parts were not
Nectaries. Sometimes possibly he may seem
to err, like UHeritier, in calling abortive
stamens by this name. Yet who knows that
their filaments do not secrete honey as wel
as the tubes of numerous flowers? And though
abortive as to Antheras, the Filament, con-
tinuing strong and vigorous, may do its of-
fice.

Honey is not absolutely confined to the
flower. The glands on the footstalks of Pas-
sion-flowers yield it, and it exudes from the
flower-stalks of some liliaceous plants.

The sweet viscid liquor in question has
given rise to much diversity of opinion re-
specting its use. Pontedera thought it was
absorbed by the seeds for their nourishment
while forming, as the yolk of the egg by the
chick. But Linnseus observes in reply, that
barren flowers produce it as well as fertile
ones, witness Urtica and Salix. In some
instances the fertile flowers only are observed
to bear honey, as Fhyllanthm and Tamils
but such cases are rare. Even Darwin says
the honey is the food of the stamens and
pistils, not recollecting that it is often lodged
in spurs or cells quite out of their reach.

270 OP THE STAMENS

There can be no doubt that the sole use of
the honey with respect to the plant is to
tempt insects, who in procuring it fertilize
the flower, by disturbing the dust of the Sta-
mens, and even carry that substance from
the barren to the fertile blossoms.

3 . St a m i N a . The Stamens, formerly called
Chives, are various in number in different
flowers, from one to some hundreds. Their
situation is internal with respect to the
parts we have been describing ; external
to the Pistils, at least in simple flowers.

These organs are essential, there being
no plant hitherto discovered, after the most
careful research, that is destitute of them,
either in the same flower with the pistils,
or a separate one of the same species.

A Stamen commonly consists of two
parts, the Filament, Filamentum, and
Anther*, A n t h era^ the former being merely
what supports the latter, which is the only
essential part. Various forms and propor-

* I submit to the opinion of Professor Martyn in
adopting this word, for the reasons given in his La?i-
guage of Botany, more especially as general practice
seems to favour its use.

AND ANTHERS. 271

tions of Filaments may be seen in the Tu-
lip, where they are six in number, thick
and short, Engl Bot. t. 63 ; the Pink,
where they are ten, much more slender,
and answering to the idea of a filament or
thread, t. 62 ; and Anemone, t. 51, where
they are numerous. They are commonly
smooth, but sometimes, as in Verbascum,
t. 58, 59, bearded. In Melaleuca, Exot.
' Bot. t. 36 and 50, they are branched;
and in Prunella, Engl. Bot. t. 96l, forked,
one pointy only bearing an Anther. In
Aristolochia, t. 398, they are wanting,
and nearly so in Potamogeton, t. 376, &c.
The Anther is the only essential part of
a Stamen. It is generally of a membranous
texture, consisting of two cells or cavities,
bursting longitudinally at their outer
edges, as in the Tulip. In Erica, t. 1013
— 15, it opens by pores near the summit,
as in the Potatoe-blossom. Very rarely
the Anther has four cells, as Tetratheca,
Bot. of N. Holl. t. 5, and Exot. Bot.
f % go* — 22. Sometimes it is ornamented

* In this plate the engraver has by mistake expressed
the section of the anther so as to look more like a ger-
men, though the original drawing was correct.

268 OF THE POLLEN.

with a crest, as in many Erica:, and the
genus Pimis. See Mr. Lambert's splendid
work.

The Pollen, or Dust, is contained in
the Anther, from which it is thrown out
chiefly in warm dry weather, when the
coat of the latter contracts and bursts.
The Pollen, though to the naked eye a
fine powder, and light enough to be wafted
along by the air, is so curiously formed,
and so various in different plants, as to be
an interesting and popular object for the
microscope. Each grain of it is commonly
a membranous bag, round or angular,
rough or smooth, which remains entire till
it meets with any moisture, being con-
trary in this respect to the nature of the
Anther; then it bursts with great force,
discharging a most subtile vapour. In
the Orchis family, and some other plants,
the pollen is of a glutinous nature, very
different from its usual aspect. See re-
marks on Mirabilis longiflora, Exot. Bot.

v. 1. 44.

The Stamens are changed to petals in
double flowers, and rendered useless. They
are often obliterated by excessive nourish-

OF THE PISTILS. 273

ment, or when the plant increases much
bv root, as in the Fiery Lily, or true
Lilium bulbiferum.

4. Pistilla. The Pistils, no less essential
than the Stamens, stand within them in
the centre of the flower, and are generally
fewer. When in a different flower, on the
same or a different plant, they are not al-
ways central. Linnaeus conceived them to
originate from the pith, and the stamens
from the wood, and hence constructed an
ingenious hypothesis, relative to the pro-
pagation of vegetables, which is not desti-
tute of observations and analogies to sup-
port it, but not countenanced by the ana-
tomy and physiology of the parts alluded
to.

Each Pistil consists of three parts. 1,
the Germen, or rudiment of the young
fruit and seed, which of course is essential;
2, the Stylus, style, various in length and
thickness, sometimes altogether wanting,
and when present serving merely to ejev&te
the third part, Stigma. This last is indis-
pensable. Its shape is various, either
T

27* OF THE GERMEN,

simple, scarcely more than a point, or
capitate, forming a little round head, or
variously lobed. Sometimes hollow, and
gaping more especially when the flower is
in its highest perfection ; very generally
downy, and always more or less moist
with a peculiar viscid fluid, which in some
plants is so copious as to form a large
drop, though never big enough to fall
to the ground. The moisture is designed
for the reception of the pollen, which ex-
plodes on meeting with it ; and hence the
seeds are rendered capable of ripening,
which, though in many plants fully form-
ed, they would not otherwise be.

The Germen appears under a variety of
shapes and sizes. It is of great moment
for botanical distinctions to observe whe-
ther it be superior, that is, above the
bases of the calyx and corolla, as in the
Strawberry and Raspberry, or inferior,
below them, as in the Apple and Pear.
Very rarely indeed the Germen is supposed
to be betwixt the calyx and corolla, of
which Sanguisorba, Engl. Hot. t. 1312, is
reckoned by Linnaeus an example; but

CHANGES IN THE HST1LS. S7 5

the corolla there has really a tube, closely
embracing the Germen. In Adoxa 9 t. 453 9
the calyx is half-inferior, the corolla su-
perior. When in botanical language we
say germen superior, it is equivalent to
flozcer inferior ; but it is sometimes more
convenient and proper, for the sake of
analogy or uniformity, to use one mode of
expression than the other.

Pistils are sometimes obliterated, though
oftener changed to petals, in double flowers,
as well as the stamens ; but I have met with
a much more remarkable change in the
Double Cherry, of the pistil into a real
leaf, exactly conformable to the proper
leaves of the tree, only smaller. By this
we may trace a sort of round in the vege-
table constitution. Beginning at the her-
bage or leaves, we proceed insensibly to
bracteas in many species of Salvia, or to
both calyx and corolla in the Garden Tu-
lip, which frequently has a leaf half green
half coloured, either in the flower or on
the stalk just below it. Anemone alpina
produces occasionally a petal among the
segments of its involucruni or bracteu.
T 2

276 OF THE SEED VESSEL AND ITS KINDS.

Geum rivale, Engl, Bot. t. 106, when
cultivated in dry gravelly ground, exhibits
such transformations in abundance. Be-
tween petals and stamens there is evidently
more connection, as to their nature and
functions, than between any other organs,
and they commonly flourish and fall to-
gether. Yet only one instance is known
of petals changing to stamens, which Dr.
Withering has commemorated, in the
Black Currant, Ribes nigrum. On the
other hand, nothing is more frequent than
the alteration of stamens to petals. Here
then the metamorphosis begins to be re-
trograde, and it is still more so in the
Cherry above mentioned, by which we re-
turn to the herbage again. — The line of
distinction seems to be most absolute be-
tween stamens and pistils, which never
change into each other ; on the contrary,
pistils, as we see, rather turn into petals,
or even into leaves.

5w Pericarpium. The seed-vessel, ex-
tremely various in different plants, is
formed of the germen enlarged, It is not

OP THE SEED-VESSEL AND ITS KINDS. 277

an essential part, the seeds being frequently
naked, and guarded only by the calyx, as
in the first order of the Linnsean class
Didy?iamia 9 of which Lamium, Engl.Bot.
t. 768, and Galeopsis, t, 667? are exam-
ples ; also in the great class of compound
flowers, Syngenesia, as well as in liumex,
t. 724, Polygonum, t. 989, the Umbelli-
ferous tribe, numerous Grasses, &c.

The use of the Seed-vessel is to protect
the seeds till ripe, and then in some way
or other to promote their dispersion, either
scattering them by its elastic power, or
serving for the food of animals in whose
dung the seeds vegetate, or promoting the
same end by various other means. The
same organ which remains closed so long
as it is juicy or moist, splits and flies
asunder when dry, thus scattering the
seeds in weather most favourable for their
success. By an extraordinary provision of
Nature, however, in some annual species of
Mesembrypithemum, natives of sandy de-
serts in Africa, the seed-vessel opens only
in rainy weather; otherwise the seeds
might, in that country, lie long exposed

§78 THE CAPSULE AND ITS KINDS.

before they met with sufficient moisture to
vegetate.

lo Capsula, a Capsule, is a dry seed-vessel
of a woody, coriaceous or membranous
texture, generally splitting into several
valves; more rarely discharging its con-
tents by orifices or pores, as in Campanula
and Papaver ; or falling off entire with
the seed. Internally it consists either of
one cell or several ; in the latter case the
parts which separate the, cells are called
dissepiment a , partitions. The central co-
lumn to which the seeds are usually at-
tached is named columella. See Datura
Stramonium, EngL Bot. t. 1288.

Gartner, a writer of primary authority
on fruits and seeds, reckons several pecu-
liar kinds of Capsules, besides what are
generally understood as such ; these are

Utriculus, a Little Bladder, which va-
ries in thickness, never opens by any
valves, and falls off with the seed. I be-
lieve it never contains more than one seed,
of which it is most commodiously, in bo-
tanical language, called an external coat,

THE CAPSULE AND ITS KINDS. 279

rather than a Capsule. Gaertner applies it
to Chenopodium, as well as to Clematis,
&c. In the former it seems a Pellicula,
in the latter a Testa, as we shall hereafter
explain.

Samara is indeed a species of Capsule,
of a compressed form and dry coriaceous
texture, with one or two cells, never
bursting, but falling off entire, and dilated
into a kind of wing at the summit or sides.
It is seen in the Elm, the Maple, the Ash,
Engl. Bot. t. 1C92, and some other plants.
This term however may well be dispensed
with, especially as it is the name of a genus
in Linnaeus ; an objection to which Co-
tyledon too is liable.

Folliculus, a Follicle or Bag, reckoned
by Linnaeus a separate kind of seed-vessel
from the Capsule, ought perhaps rather to
be esteemed a form of the latter, as Gaert-
ner reckons it. This is of one valve and
one cell, bursting lengthwise, and bearing
the seeds on or near its edges, or on a re-
ceptacle parallel therewith. Instances are
found in Vinca, ^.514, Paonia, t. 1513,
and Embothrium, Pot. of New Holland,
t.7—10.

280 THE SILiaUA.

Coccum of Gaertner, separated by him
from capsules, is a dry seed-vessel, more
or less aggregate, not solitary, whose sides
are elastic, projecting the seeds with great
force, as in Euphorbia ; also Boro?iia,
Tracts on Nat* History, t. 4 — 7» This
seems by no means necessary to be esteemed
otherwise than a sort of capsule.
2- Siliqua, a Pod, is a long dry solitary
seed-vessel of two valves, separated by a
linear receptacle, along each of whose
edges the seeds are ranged alternately, as
in the class Tetradynamia. See Cheiran-
thtis, Engl. Bot. t. 462, and Cardamine,
t. 80 ; also Bignonia echinata, figured by
Gaertner, t. 52. f. 1, which, though cau-
tiously called by him a capsula siliquosa
only, is as true a Siliqua, according to his
own definition, and every body's ideas, as
possible ; so is also that of Chelidonium.
He justly indeed names the fruit ofPceonia,
capsula leguminosa, a follicle with him
being a single-valved capsule, with the
seeds marginal as in a legume.

Silicula, a Pouch, is only a Pod of a
short or rounded figure, like Draba verna,
Engl Bot. t. 586.

THE LEGUMEN. 281

3 * Legumen, a Legume, is the peculiar soli-
tary fruit of the Pea kind, formed of two
oblong valves, without any longitudinal
partition, and bearing the seeds along one
of its margins only. See Engl. Bot.
t. 1046", 803, &c. The Tamarind is a
Legume filled with pulp, in which the
seeds are lodged. The Capsules of Helle-
bores and some other plants allied thereto,
justly indicated by Gaertner as approach-
ing very nearly to the definition of Le-
gumes, differ essentially in not being soli-
tary, and in consisting each but of one
valve. Some Larkspurs indeed bear such
capsules solitary, but analogy teaches us
their true nature.

When a Legume is divided into several
cells, it is always by transverse constric-
tions, never by a separate longitudinal
partition ; see Dolichos purpureas, Exot.
Bot. t. 74.

Sometimes this kind of fruit lodges but
one seed, as in many species of Tr'i folium ;
see Engl. Bot. 1. 1048, also Viminaria denu-
data, Exot. Bot. t. 27. It is only by analogy
that such are known to be Legumes.

£8S THE DKUFA, POMUM AtfD BACCA,

4 « Driipay a Stone-fruit, has a fleshy coat,
not separating into valves, containing a
single hard and bony Nut, to which it is
closely attached ; as in the Peach, Plum,
Cherry, &c. ; see Engl. Bot. t. 706 and
l^d3. The Cocoa-nut is a Drupa with a
less juicy coat.

Sometimes the Nut, though not sepa-
rating into distinct valves, contains more
than one cell, and consequently several
seeds. Instances are found in Cornus,
t. 249, Gartner, t. 26, and Oka, the
Olive, Fl. Grcec. t. 3, though one cell of
the latter is commonly abortive.

5 - Pomum, an Apple, has a fleshy coat like
the Drupa, but containing a Capsule with
several seeds, as in common Apples and
Pears ; see Pyrus domestica, t. 350.

This is comprehended by Giertner un-
der the different kinds of Bacca, it being
sometimes scarcely possible to draw the
line between them; witness the Linnaean
genus Sorbus*

6. Bacca, a Berry, is fleshy, without valves,
6

THE BACCA. 283

containing one or more Seeds, enveloped
with pulp. It becomes more juicy inter-
nally as it advances to maturity, quite
contrary to the nature of a Capsule, though
the difference between these two unripe
fruits may not be discernible, and though
some true Berries, when fully ripe, finally
become of a dry and spongy texture ; but
they never open by valves or any regular
* orifice. Examples of a Bacca are seen in
Atropa Belladonna, Engl. Bot. t. 592,
and Ribes, f. 1289— 92. The same part
in Hedera, t. Vlbl, is of a more mealy
substance. In Cucubalus^ t. 1577, the
coat only is pulpy. In Trienialis, t. 15,
the coat becomes very dry and brittle as
soon as ripe, and the cavity of the fruit is
nearly filled by a globular columella. See
Gartner, /. 50.

Bacca composita, a Compound Berry,
consists of several single ones, each con-
taining a seed, united together, as in Rto-
bus, the Raspberry, Bramble, &c, Engl.
Bot, t. 715, 716, 826, 8*7, Each of the
separate parts is denominated an Acinus,
ox Grain, which term Gartner extends to

SS4 SPURIOUS KINDS OF BACCJE.

the simple many-seeded berries of the Vine,
Gooseberry, &c.

The Orange and Lemon are true Ber-
ries, with a thick coat. The Melon and
Cucumber tribe have a peculiar sort of
Berry for which Gaertner uses the name of
Pepo, Gourd; and he defines it a Berry
whose cells, together with the seeds, are
remote from the axis or centre, the seeds
being inserted into the sides of the fruit.
Passiflora suberosa, Exot. Bot. t. 28,
shows this insertion, being nearly allied to
the same tribe ; but in this genus the pulp
invests each seed separately, forming Acini
within the common cavity.

Some fruits ranged by Linnaeus as Drnpce
with many seeds, on account of the hard-
ness of the shells of those seeds, are best
perhaps, on account of their number, con-
sidered by Gaertner as Baccce. Among
these are Mespilus, the Medlar.

There are several spurious kinds of ber-
ries, whose pulp is not properly a part of
the fruit, but originates from some other
organ. Thus, in the Mulberry, as well as
the Strawberry Spinach, Blitum, Curt.

SPURIOUS KINDS OF BACCLE. 285

Mag. t. 276, the Calyx after flowering
becomes coloured and very juicy, invest-
ing the seed, like a genuine berry. The
Corolla of CommeUna Zanonia undergoes
a similar change, forming a black \ery
juicy coat to the capsule, being totally al-
tered both in shape and substance from its
appearance in the flower. In the Juniper,
EngL Bot. t. 1100, a few scales of the
fertile catkin become succulent, and coalesce
into a globular berry with three or more
seeds, to which Gaertner applies the term
galbuhis, the classical name of the Cypress
fruit, which last however is as true a stro-
bilus or cone as that of the Fir. In the
Yew, t. 746, some have thought it a calyx,
others a peculiar kiad of receptacle, which
becomes red and pulpy, embracing the
seed. Lamarck has, in his Encyclopedic,
v. 3. 228, considered this fruit as a real
bacca or drupa, with the idea or definition
of either of which it cannot by anv means
be made to accord, being open at the top,
and having no connection with the $tigma 9
which crowns the seed itself. The same
writer mistakes for a calyx the scales, which

286 THE STROBILUS.

analogy shows to be bracteas ; and I can-
not bat think Jussieu and Gaertner more
correct in their ideas of this singular fruit,
when they call the pulpy part in- question
a receptacle, though the term calyx seems
less paradoxical, and is perhaps still more
just*. We do not know enough of Taxus
tiucifera to draw any conclusions from
thence. See Gcertner, t. 91. In the Straw-
berry, Engl. Bot. t. 1524, what is com-
monly called the berry is a pulpy recepta-
cle, studded with naked seeds. In the
Fig, Gcertntr, ^.91? the whole fruit is a
juicy calyx, or rather common receptacle,
containing in its cavity innumerable florets,
each of which has a proper calyx of its
own, that becomes pulpy and invests the
seed, as in its near relation the Mulberry.
The Paper Mulberry of China is indeed an
intermediate genus between the two, be-
ing as it were a Fig laid open, but with-
out any pulp in the common receptacle.

7- Strobilus, a Cone, is a Catkin hardened

* Hernandia, Gcertn, t. 40, has a similar, though
not succulent, calyx, and thr green cup of the Hazle-
nut is equivalent to it.

THE SEEDS. 287

and enlarged into a Seed-vessel, as in Pi-
mis, the Fir.

In the most perfect examples of this kind
of fruit the Seeds are closely sheltered by
the scales as by a capsule, of which the
Fir, Cypress, &c, are instances. In the
Birch and Alder they have a kind of cap-
sule besides, and in the Willow and Poplar
a stalked bivalve capsule, still more sepa-
rate from the scales. The Plane-tree, Pla-
tanus, the Liquidambar and the Compto?iia,
have globular catkins, in which bristles or
tubercles supply the place of scales. See
Gccrtner, t, 90.

. Semina. The Seeds are the sole "end
and aim" of all the organs of fructifi-
cation. Every other part is, in some man-
ner, subservient to the forming, perfect-
ing, or dispersing of these. A seed con-
sists of several parts, some of which are
more essential than others, and of these I
shall speak first.

Embryo, the Embryo, or Germ, is the
most essential cf all, to which the rest are
wholly subservient, and without which jio

f88 THE EMBRYO.

seed is perfect, or capable of vegetation,
however complete in external appearance.
Linnaeus, after Ceesalpinus, names it the
Corculum, or Little Heart, and it is the
point whence the life and organization of
the future plant originate, as we have al-
ready explained, p. 96. In some seeds it
is much more conspicuous than in others.
The Walnut, the Bean, Pea, Lupine, &c,
show the Embryo in perfection. Its inter-
nal structure, before it begins to vegetate,
is observed by Gaertner to be remarkably
simple, consisting of an uniform medullary
substance, enclosed in its appropriate bark
or skin. Vessels are formed as soon as the
vital principle is excited to action, and
parts are then developed which seemed not
previously to exist, just as in the egg of a
bird. In position, the Embryo is, with
respect to the base of the whole flower or
fruit, either erect, as in the Dandelion and
other compound flowers, reversed as in the
Umbelliferous tribe, or horizontal as in the
Date Palm, Gcertner, t. 9- In situation
it is most commonly within the substance
of the seed, and either central as in Un>

COTYLEDONS. 289

belliferous plants, or excentric, out of the
centre, as in Coffee ; in Grasses however it
is external. Its direction is either straight,
curved, or even spiral, in various instances.
The Embryo of seeds that have a single
cotyledon, or none at all, is peculiarly
simple, without any notch or lobe, and is
named by Gsertner Embryo monocotyk-
floneus.

Cotyledones, the Cotyledons or Seed-
lobes, are immediately attached to the
Embryo, of which they form, properly
speaking, a part. They are commonly two
in number ; but in Pinus, and Dombeya,
the Norfolk Island Pine, they are more,
as already mentioned, p. 98, When the
seed has sufficiently established its root,
these generally rise out of the ground, and
become a kind of leaves. Such is the true
idea of the organs in question, but the
same name is commonly given to the body
of the seed in the Grass and Corn tribe,
the Palms, and several other plants, thence
denominated monocotyledones, because the
supposed Cotyledon is single. The iihune
of this part we shall presently explain. It
u

290 OF THE ALBUMEN,

neither rises out of the ground, nor per-
forms the proper functions of a Cotyledon,
for what these plants produce is, from the
first, a real leaf; or, if the plant has no
leaves, the rudiment of a stern, as in Cus-
cuta. In either case, the part produced is
solitary, never in pairs ; hence Gcertner
was led to reckon Cyamas Nelumbo, Exot.
Bot. t. 31, 32, among the monoeotyle-
donous plants, the body of its seed remain-
ing in the earth, and the leaves springing
one at a time from the Embryo, just as in
the Date Palm, Wheat, Barley, &c.

The Seed-lobes of Mosses, according to
the observations of Hedwig, Fund, part 2.
t. 6; are above all others numerous and
subdivided, as well as most distinct from
the proper leaves ; so that these plants are
very improperly placed by authors among
such as have no Cotyledons, a measure
originating probably in theory and ana-
logical reasoning rather than observation.

Albumen, the While, is a farinaceous,
fleshy, or horny substance, which makes up
the chief bulk of some seeds, as Grasses,

OR WHITE. 2gi

Corn, Palms, Lilies, never rising out of the
ground nor assuming the office of leaves,
being destined solely to nourish the ger-
minating embryo, till its roots can perform
their office. In the Date Palm, Gcertner,
t. 9 ? this part is nearly as hard as a stone ;
in Mirabilis, Exot. Hot. t. 23, it is like
wheat flour. It is wanting in several tribes
v of plants, as those with compound, or with
cruciform flowers, and the Cucumber or
Gourd kind, according to Goertner. Some
few leguminous plants have it, and a great
number of others which, like them, have
cotyledons besides. We are not however
to suppose that so important an organ is
altogether wanting, even in the above-
mentioned plants. The farinaceous matt r- ,
destined to nourish their embryos, is un-
questionably lodged in their cotyledons,
whose sweet taste as they begin to germi-
nate often evinces its presence, and that it
has undergone the same chemical change
as in Barley. The Albumen of the Nut-
meg is remarkable for its eroded variegated
appearance, and aromatic quality ; the co-
tyledons of this seed are very small.
u 2

292 OF THE VITELLUS,

Vitellus, the Yolk, first named and fully
illustrated by Gaertner, is less general than
any of the parts already mentioned. He
characterizes it as very firmly and insepa-
rably connected with the Embryo, yet
never rising out of the integuments of the
seed in germination, but absorbed, like
the Albumen, for the nourishment of the
Embryo. If the Albumen be present, the
Vitellus is always situated between it and
the Embryo, and yet is constantly distinct
from the former. The Vitellus is esteemed
by Gaertner to compose the bulk of the
seed in Fuci, Mosses and Ferns, as well as
in the genus Zamia, closely allied to the
latter, see his t. 3, and even in Ruppia,
Engl. Bot. t. 156, and Cyamus. In the
natural order of Grasses the part under con-
sideration forms a scale between the Mm-
bryo and the Albumen.

I cannot but think that the true use of
the Vitellus may be to perform the func-
tions of a Cotyledon with regard to air if
not to light, till a real leaf can be sent
forth, and that the " subterraneous Coty-
ledons" of Gaertner in the Horse Chesnut

OR YOLK. 293

and Garden Nasturtium are, as he seems to
indicate in his Introduction, p. 151, rather
of the nature of a Vitellus. It does not
appear that any plant with genuine ascend-
ing Cotyledons is likewise furnished with
this organ ; on the other hand, it com-
monly belongs to such as have the most
copious Albumen, and therefore should
• seem to answer some other end than mere
nutriment, which is supplied by the latter.
We learn from the above inquiries, that
the old distinction between plants with one
Cotyledon and those with several may still
be relied on, though in the former the
part which has commonly been so deno-
minated is the Albumen, as in Corn, the
real Cotyledon of which is the scale or
Vitellus, which last organ however seems
wanting in Palms, Lilies, &c, such having
really no Cotyledon at all, nor any thing
that can perform its office, except the stalk
of their Embryo*. In the Horse Chesnut,
Oak and Walnut possibly, whose sred-lobes

* This may answer the purpose of a Cotyledon, just as
the stems of many plants fulfil the office of leaves.

2g4 TESTA, THE SKIN.

do not ascend, the functions of a real Coty*
ledon, as far as air is concerned, and those
of the Albumen may be united in these
lobes, as is the case with most Leguminous
plants ; which is rendered more probable,
as several of the latter have the corre-
sponding parts likewise remaining under
ground. Hence the divided Vitellus of
the Cyamus is to be considered as a pair
of subterraneous Cotyledons, and the plant
consequently ranges near its natural allies
the Poppy tribe, as Mr. Salisbury, without
the aid of physiology, has shown in the
Annals of Botany, v, 3, p. 70, 75.

Testa, the Skin, contains all the parts of
a seed above described, giving them their
due. shape ; for the skin is perfectly formed,
while they are but a homogeneous liquid.
This coat differs in thickness and texture
in different plants. It is sometimes single,
but more frequently lined with a finer and
very delicate film, called by Gartner Mem-
bruna, as may be seen in a Walnut, and
the kernel of a Peach, Almond, or Plum.
In the Jasmine a quantity of pulp is lodged

HILUMj THE SCAR. 2 & 5

between the Memhrana and the Testa,
constituting a pulpy seed, semen baccatunu
which is distinct from the Acinus, or grain
of a compound berry in the Raspberry,
the seed of the latter having its proper
double covering within the pulp. The
Testa bursts irregularly, and only from the
swelling of its contents in germination.

Hilum, the Scar, is the point by which
the seed is attached to its seed-vessel or
receptacle, and through which alone life
and nourishment are conveyed for the per-
fecting its internal parts. Consequently
all those parts must be intimately con-
nected with the inner surface of this scar,
and they are all found to meet there, and
to divide or divaricate from that point,
more or less immediately. In describing
the form or various external portions of
any seed, the Hilum is always to be con-
sidered as the base. When the seed is
quite ripe, the communication through this
channel is interrupted : it separates from
the parent plant without injury, a Scar
bein^ formed on each. Yet the Hilum is

$9& OF THE PELLICULA

so far capable of resuming its former na-
ture, that the juices of the earth are im-
bibed through it previous to germination.

There are various accessory parts, or
appendages, to seeds, which come under
the following denominations.

Pellicula, the Pellicle, called by Gaertner
Epidermis, closely adheres to the outside of
some seeds, so as to conceal the proper co-?
lour and surface of their skin, and is either
membranous, and often downy, as in Con-
volvulus, or mucilaginous, not perceptible
till the seed is moistened, as in Salvia ver-
benaca, Engl. Bot. t. 154. Perhaps the
covering of the seed in Clienopodium, called
by Gtertner Utriculus, is merely a Pelli-
cula.

Arillus, the Tunic, is either a complete or
partial covering of a seed, fixed to its base
only, and more or less loosely or closely
enveloping its other parts, Of this nature
is the pulpy orange-coloured coat in Eu-
onymus, t. 362, the beautiful scarlet cup
in Afzelia, and the double membranous
«oat in Hippophde, t. 425, which last in-
vests the seed within the pulp of the berry.

AND ARILLUS. 297

The outer of these coats only is described
by Gaertner, as a peculiar membrane lining
the cell of the berry ; his " integument urn
duplex" refers to the testa, which I men-
tion only to prevent misapprehension. The
Mace which envelopes the Nutmeg is a
partial Arillus, beautifully drawn in Gaert-
ner, t. 41. Narthecium, Engl. Bot. t. 535,
has a complete membranous tunic, elon-
gated beyond the seed at each end, as in
many of the Orchis tribe ; and such seeds,
acquiring thence a light and chaffy appear-
ance, have been denominated scobiformia,
whence Bergius was perhaps led, very un-
scientifically, to call the seeds of ferns lite-
rally scobs or sawdust ! An elastic pouch-
like Arillus, serving to project the seeds
with considerable force, occurs in Oralis,
t. 762 and 1/26. In the natural order
of Rutacece the same part, shaped also like
a pouch lining each cell of the capsule, is
very rigid or horny ; see Dictamnus albus,
or Fraxinella, Gartn. t. 69, and Boronia,
Tracts on is at. Hkt. t. 4 — 7. Besides
this coincidence, there are many common
points of affinity between these plants and

OF THE ARILLUS

Ova lis, concerning colour, flavour, habit
and structure. Fagonia and its allies form
the connecting link between them, which
Gartner and Jussieu did not overlook.
We have pointed out this affinity in Eng-
lish Botany, p. 762, and it is confirmed by
the curious circumstance of Jacquin's Or-
alis rostrata, Oxal. t. 22, having the very
appendages to its filaments which make a
peculiar part of the character of Boronia.

It is not easy to say whether the va-
rious, and frequently elaborate, coat of the
seed among the rough-leaved plants, Bo-
?*ago, Anchusa, Lithospermum, Cynoglos-
sum, Engl. Bot. t. 921, &c, should be
esteemed an Arillus or a Testa ; but the
latter seems most correct, each seed hav-
ing only a simple and very thin membra-
nous internal skin besides. Gsertner there-
fore justly uses the term Nut for the seeds
in question. The same may be observed
of Ranunculus, Myosurus, see Engl. Bot.
t. 435, Clematis, Anemone, &c, whose
external coats are no less various and ela-
borate ; yet such seeds are as truly naked
as those of the Didynamia class, figured

AND PAPPUS. 299

in Goertner, t. 66, each having a double
skin and no more, which is one covering
less than even the genuine nut of the stone
fruit, or of the Con/his. In Geranium^
Malta, &c, what has often been called
Arillus, is rather a kind of Capsule, not
only because their seeds have a double or
even triple skin, quite unconnected with
this outer cover, but because the latter is
analogous to other Capsules.

The loose husky covering of the seed in
Carex is surely an Arillus. See Engl. Bet.
also the Rev. Mr. Wood's observations on
this genus in Dr. Rees's Cyclopaedia^ and
Gaertner, v. 1. 13. This seed has besides a
doable Testa, though most of the true
Grasses have but one, which in ground
Corn constitutes the bran, the husks of
the blossom being the chaff.

Pappus, the Seed-down, is restrained
by Gaertner to the chaffy, feathery, or
bristly crown of many seeds that have no
Pericarpium, and which originates from a
partial calyx crowning the summit of each
of those seeds, and remaining after the

300 OF THE PAPPUS,

flower is fallen. Instances of this are the
feathery appendages to the seeds of Dan-
delion, Engl. Bot. t. 510, and GoatVbeard,
t. 434, in which the part in question is
elevated on a footstalk. In Carduus,
t- 973 — 6, it is sessile, though still feathery ;
but in Cichoriam, t. 539 ? it consists of
mere chaffy teeth, more clearly evincing
its affinity to a Calyx. In Scabiosa it is
double. In Bidens, t. 1113, 1114, the
Pappus is formed of 2, 3 or 4 rigid barbed
bristles. The use of this organ is evi-
dently to transport seeds to a distance
from their native spot, either by resigning
them to the power of the wind, or by at-
taching them to the shaggy coats of ani-
mals. In due time the feathery crown
separates, and leaves the seed behind it,
which happens sooner with the Thistle
than most other plants. Hence the vacant
down of that genus is frequently seen
wafted in light masses over a whole coun-
try ; which has not escaped the notice of
poets.

The same term is used by the generality
of botanists for the feathery crown of

CAUDA, ROSTRUM, ETC. 301

seeds furnished with a capsule, as Epilo-
biam t. 1177? Asclepias, Cynanchum, &c,
Gar til. t. 117, as well as for a similar
appendage to the base or sides of any
seeds, as Satis, Engl. Bot. t. 183, 1403,
Eriophorum, t. 873, &c, neither of which
can originate from a Calyx. For the
former of these Gaertner adopts the term
Coma, for the latter Pubes, which last also
serves for any downiness or wool about the
Testa of a seed, as in the Cotton plant,
and Blandfordia nobilis, Exot. Bot. t. 4.

Cauda, a Tail, is an elongated, generally
feathery, appendage to some Seeds, formed
from the permanent style, as in Clematis,
Engl. Bot. t. 612, Dryas, t. 451, Geum,
t. 1400.

Rostrum, a Beak, mostly applies to some
elongation of a Seed-vessel, originating
likewise from the permanent style, as in
Geranium, t. 272, Helkborus, t. 200,
though it is also used for naked seeds, as
Scandix, t. 1397-

Ala, a Wing, is a dilated i a

30 £" APPENDAGES

appendage to Seeds, as in Emboihrium?
Bot. of N* HolL t. 7? Banksia, Concilium.
Blgnonia echinata, Garin. t. 52, Bhutan-
thus, Engl. Bot. t. 657, serving to waft
them along in the air. Gaertner wished to
confine this term to a membranous expan-
sion of the top or upper edge of a Seed or
Seed-vessel, using mar go membranaceus
for one that surrounds the whole, but he
has not adhered to it in practice. Cap-
sules are sometimes furnished with one
wing, as the Ash, oftener with several, as
TIalesia, Acer, Begonia, &c. In Seeds
the Wing is commonly solitary, except
some Umbelliferous plants, as Thapsia,
Gccrtn. t.21.

Seeds are occasionally furnished with
Spines, Hooks, Scales, Crested appendages,
particularly a little gland-like part near
the Scar, sometimes denominated Stro-
phiolum, as in Asarum, Gccrtn. t. 14,
Bossuea, Ventenat. J arch cle Ctls. t. 7,
Platylobium, Bot. of N. HolL t. 6, Vleos,
Spariium, Sec. In general however smooth-
ness is characteristic of a seed, by which
it best makes its way into the soft earth,

TO SEEDS. 303

though sometimes it is barbed, or at least
its covering, as in Siipa, Engl. Bot. t. 1356,
that it may not easily be withdrawn again
by the powerful feathery appendage of that
plant, which after having by its circumvo-
lutions forced the seed deeper and deeper,
breaks off at a joint, and flies away.

The various modes by which seeds are
dispersed cannot fail to strike an observing
mind with admiration. Who has not list-
ened in a calm and sunny day to the
crackling of Furze bushes, caused by the
explosion of their little elastic pods; nor
watched the down of innumerable seeds
floating on the summer breeze, till they
are overtaken by a shower, which moisten-
ing their wings stops their further flight,
and at the same time accomplishes its final
purpose, by immediately promoting the
germination of each seed in the moist earth :
How little are children aware, as they blow
away the seeds of Dandelion, or stick
Burs in sport upon each other's clothes,
that they are fulfilling one of the gneai
ends of Nature! Sometimes the Caljix,
beset with hooks, forms the bur, as in

304 THE RECEPTACLE.

Arctium Lappa, Engl. Boi. t. 1228 :
sometimes hooks encompass the fruit itself,
as in Xant hium, and some species of Ga-
lium, particularly G. Aparine, t. 816.
Plants thus furnished are observed by
Linnaeus to thrive best in a rank manured
soil, with which, by being conveyed to
the dens of wild animals, they are most
likely to meet. The Awns of grasses an-
swer the same end. Pulpy fruits serve
quadrupeds and birds as food, while their
seeds, often small, hard and indigestible,
pass uninjured through the intestines, and
are deposited far from their original place
of growth, in a condition peculiarly fit for
vegetation. Even such seeds as are them-
selves eaten, like the various sorts of nuts,
are hoarded up in the ground and occa-
sionally forgotten, or carried to a distance,
and in part only devoured. Even the
ocean itself serves to waft the larger kinds
from their native soil to far-distant shores.

7. Receptaculum. The Receptacle is the
common base or point of connexion of the
other parts of fructification. It is not al-

THE RECEPTACLE.

ways distinguishable by any particular
figure, except in compound flowers con-
stituting the Linnaean class Sijngenesia, in
which it is very remarkable and important.
In the Daisy, Engl. Bot. i. 424, it is coni-
cal ; in Chrysanthemum, t. 601, convex ;
in others flat, or slightly concave. Picris,
t. 972, has it naked, that is, destitute of
' any hairs or scales between the florets or
seeds ; Cardans, t. 675, hairy ; Anthemis,
t. 602, scaly ; and Onopordum, t. 977,
cellular like a honey-comb. ,-On this and
the seed-down are founded the most solid
generic characters of these plants, admi-
rably illustrated by the inimitable Gaertner.
The term Receptacle is sometimes ex-
tended by Linnaeus to express the base of
a flower, or even its internal part between
the stamens and pistils, provided there be
any thing remarkable in such parts, with-
out reference to the foundation of the
whole fructification. It also expresses the
part to which the seeds are attached in a
seed-vessel.'

306 VARIOUS KINDS OF FLOWERS,

Having thus explained the various organs
of fructification, we shall udd a few remarks
concerning flowers in general, reserving the
functions of the Stamens and Pistils, with
the Linnsean experiments and inquiries rela-
tive to that curious subject, for the next
chapter.

A flower furnished with both calyx and
corolla is called Jios comphtus, a complete
flower; when the latter is wanting, incom-
pktiis ; and when the corolla is present with-
out the calyx, nudm, naked. When the
stamens and pistils are both, as usual, in one
flower* 4;hat flower is called perfect, or united ;
when they are situated in different flowers of
the same species, such 1 would call separated
flowers; that which has the stamens being
named the barren flower, as producing no
fruit in itself, and that with pistils the fertile
one, as bearing the seed. If this separation
extends no farther than to different situa-
tions on the same individual plant, Lumens
calls such flowers monoici, monoecious, as
confined to one house or dwelling ; if the
barren and fertile flowers grow from two se-
parate roots, they are said to be dioici, dice-

COMPOUND FLOWERS. 30?

cious. Some plants have united flowers and
separated ones in the same species, either
from one, two or three roots, and such are
called polygamous, as making a sort of com-
pound household.

A Compound flower consists of numerous
florets, jiosculi, all sessile on a common undi-
vided Receptacle, and enclosed in one conti-
guous Calyx or Btrianthiittn. It is also
essential to this kind of flower that the An-
thers should be united into a cylinder, to
which only the genus Tussilago affords one or
two exceptions, and Kuhnia another ; and
moreover, that the Stamens should be 5 to
each floret, Sigesbeckia Jloscttlosa of LTIeri-
tier, Stirp. Nov. t. 19? alone having but 3.
The florets are always monopetalous and su-
perior, each standing on a solitary naked
seed, or at least the rudiments of one, though
not always perfected. Some Compound flow-
ers consist of very few florets, as Humeu ele-
gans, Exot. Bot. t. 1, Prenqnthes muralis,
EnsU Dot t. 457; ethers of many, as the
Thistle, Daisy, Sunflower, &c. The florets
themselves are of two kinds, ftga Ztftfi, ligulate,
sh^p.ed kke a strap or ribband, with 3 ar 5
^ x 2

?©8 AGGREGATE FLOWEIIS.

teeth, as in Tragopogon, t. 434, and the
Dandelion ; or tubulosi, tubular, cylindrical
and 5-cleft, as in Oarduus, t. 107 5 and Tana-
cctum, t. 1220* The marginal white florets
of the Daisy are of the former description,
and compose its radius, or rays, and its yel-
low central ones come under the latter deno-
mination, constituting its discus, or disk. The
disk of such flowers is most frequently yel-
low, the rays yellow, white, red, or blue.
No instance is known of yellow raj T s with a
white, red, or blue disk.

An Aggregate flower has a common undi-
vided Receptacle, the Anthers all separate
and distant, Jetstone only, Engl. Bat. t 882.
having them united at the base, but not into
a cylinder, «ad the florets commonly stand
en stalks, each having a single or double par-
tial calyx. Such flowers have rarely any in-
■clination to yellow, but arc blue, purple, or
white. Instances a re found in Scdhiosa, t. 659
and 1511, Dipsacus, t. 1()3 C 2 and 8/7, and
the beautiful Cape genus Froiea.

Such is the trite .ilea of an Aggregate
Sow ;. but I ::v.vv i? eivurn&fitejs, under that

AGGREGATE FLOWEKS. 309

denomination, 7 kinds, his favourite number ;
these are,

1. The Aggregate flower properly so called,
as just mentioned.

2. The Compound flower previously described.

3. The Amentaceous flower, or Catkin, of
which we have spoken p. 248.

4. The Glumose, or Chaffy flower, peculiar
to the Grasses, see p. 250.

5. The Sheathed flower, whose commpn re-
ceptacle springs from a Sheath, as in Arum.

6. The Umbellate ; and

?. The Cy mose flowers, concerning which
two last a few observations are necessary.

Linnoeus and his friend Artedi thought
the great natural umbelliferous order could
not be divided into good and distinct ge-
nera by the seeds or parts of the flower,
without taking into consideration the general
and partial involucre! leaves, which they
therefore chose to consider as a part of the
fructification, and defined as a calyx remote
from the flower. The rays of the umbel,
of course, became the subdivisions of a

310 AGGREGATE AND

branched receptacle, and the whole umbel
was considered as one aggregate flower. It
necessarily followed that a Cyme, see p. 237,
must be considered in the same light, nor
did the sagacity of Linnaeus overlook the
arguments in favour of this hypothesis. Many
of the umbelliferous tribe, as Heracleum,
t. 939, Caucalis, Coriandrum, &c, have their
marginal flowers dilated, radiant, and more
or less inclined to be imperfect or abortive,
thus evincing an analogy with real compound
flowers like the Sunflower, which analogy is
still more striking between Oenanthe, t. 363,
347, 348, and the Marigold, Calendula. So
the cymose plants, as Viburnum Opulus,
t. 332, bear dilated and abortive marginal
flowers, and Hydrangea horttnsis, Sm. Ie.
Viet. t. 12, has scarcely any others, Cornus
sanguinea, Engl Bot. U 249, has a naked
cyme, C. Sueeica y t. 310, an umbel accom-
panied by coloured bracteas, or, as Linnaeus
judged, a coloured involucrnm, proving the
close affinity between these two modes of in-
florescence.

Notwithstanding all this, I presume to dis~
sent from the above hypothesis, as offering

COMPOUND FLOWERS. 311

too great violence to Nature, and swerving
from that beautiful and philosophical Lin-
nsean principle, of characterizing genera by
the fructification alone ; a principle which
those who are competent to the subject at
all, will, I believe, never find to fail. The
seeds and flowers of the umbelliferous family
are quite sufficient for our purpose, while the
involucrum is very precarious and change-
able ; often deficient, often immoderately
luxuriant, in the same genus. In the cymose
plants every body knows the real parts of
fructification to be abundantly adequate, the
involucrum being of small moment ; witness
that most natural genus Cornus. For all
these, and other reasons, to particularize
which would lead me too far, I have, p. 236,
reckoned the Umbel and Cyme modes of
flowering, and not themselves aggregate
flowers.

318

CHAPTER XX,

OF THE PECULIAR FUNCTIONS OF THE
STAMENS AND PISTILS, WITH THE EX.
PERIMENTS AND OBSERVATIONS OF
LINNAEUS AND OTHERS ON THAT SUB-
JECT.

The real use of the Stamens of Plants was
long a subject of dispute among philosophers,
till Linnaeus, according to the general opi-
nion at present, explained it beyond a possi-
bility of doubt. Still there are not wanting
persons who from time to time start objec-
tions, prompted either by a philosophical
pursuit of truth, or an ambitious desire of
distinguishing themselves in controverting so
celebrated a doctrine, as some have written
against the circulation of the animal blood.
I propose to trace the history of this doc-
trine^ and especially to review the facts and

FUNCTIONS OP STAMENS AND PISTILS. 313

experiments' upon which Linnaeus founded
his opinion, as well as the objections it has
had to encounter. It would be endless, and
altogether superfluous, to bring forward new
facts in its support, nor shall I do so, except
where new arguments may render such a
measure necessary.

The Stamens and Pistils of flowers have,
from the most remote- antiquity, been con-
sidered as of great importance in perfecting
the fruit. The Date Palm, from time imme-
morial a primary object of cultivation in the
more temperate climates of the globe, bears
barren and fertile flowers on separate trees.
The ancient Greeks soon discovered that in
order to have abundant and well-flavoured
fruit, it was expedient to plant both trees
near together, or to bring the barren blos-
soms to those which were to bear fruit ; and
in this chiefly consisted the culture of that
valuable plant. Tournefort tells us that
without such assistance dates have no kernel,
and are not good food. The same has long
been practised, and is continued to this very
day in the Levant, upon the Pistqcia, and
the Fig.

314 FUNCTIONS O?

At the revival of learning botanists were
more occupied in determining the species,
and investigating the medical properties of
plants, than in studying their physiology*
and when after a while the subject in ques-
tion was started, some of them, as Morison,
Tournefort and Pontedera, uniformly treated
with great contempt the hypothesis which
has since been established. We shall, as we
proceed, advert to some of their arguments.

About the year 1676, Sir Thomas Milling-
ton, Savilian Professor at Oxford, is recorded
to have hinted to Dr. Grew that the use of
the Stamens was probably to perfect and
fertilize the seed. Grew adopted the idea,
and the great Ray approved it. Several other
botanists either followed them, or had pre-
viously conceived the same opinion, among
which R. J. Camerarius, Professor at Tu-
bmen towards the end of the seventeenth
century, was one of the most able and ori-
ginal. Vaillant wrote an excellent oration on
the subject, which being hostile to the opi-
nions of Tournefort, lay in obscurity till pub-
lished by Boerhaave. Blair and Bradley as-
sented in England, and several continental

STAMENS AND PISTILS. 315

botanists imbibed the same sentiments.
Pontedera, however, at Padua, an university
long famous, but then on the decline, and
consequently adverse to all new inquiry and
information, in 1720 published his Antho-
logia, quite on the ether side of the ques-
tion.

Linnaeus, towards the year 1732, reviewed
all that had been done before him, and clearly
established the fact so long in dispute; in his
Fundamenta and Philosopkia Botanica. He
determined the functions of the Stamens and
Pistils, proved these organs to be essential
to every plant, and thence conceived the
happy kfea of using them for the purpose of
systematical arrangement. In the latter point
his merit was altogether original : in the former
he made use of the discoveries and remarks
of others, but set them in so new and clear
a light, as in a manner to render them his
own.

We have already mentioned, p. 138, the
two modes by which plants are multiplied,
and have shewn the important difference be-
tween them. Propagation by seed is the only
genuine reproduction of the species, and it

3t6 FUNCTIONS OF

now remains to prove that the essential or-
gans of the flower are indispensably requisite
for the perfecting of the seed.

Every one must have observed that the
flower of a plant always precedes its fruit.
To this the Meadow Saffron, Engl. Bot. 1. 133,
seems an objection, the fruit and leaves be-
ing perfected in the spring, the blossoms not
appearing till autumn ; but a due examina-
tion will readily ascertain that the seed-bud
formed in autumn is the very same which
comes to maturity in the following spring.
A Pine-apple was once very unexpectedly
cited to me as an instance of fruit being
formed before the flower, because the green
fruit in that instance, as in many others, is
almost fully grown before the flowers expand.
The seeds however, the essence of the fruit,
are only in embryo at this period, just as in
the germen of an Apple blossom.

It was very soon ascertained that flowers
are invariably furnished with Stamens and
Pistils, either in the same individual, or two
of the same species, however defective they
may be in other parts ; of which IJippuris,
Engl Bot. t. 763, the most simple of bios-

STAMENS AND PISTILS. 317

soms, is a remarkable example. Few bota-
nists indeed had detected them in the Lemna
or Duck-weed, so abundant on the surface of
still waters, and Valisneri alone for a long time
engrossed the honour of having; seen them,
In our days however they rewarded the re-
searches of the indefatigable Ehrhart in Ger-
many, and on being sought with equal acute-
ness, were found in England. Three species
have been delineated in Engl. Bot. t. 926>
1095 and 1233, from the discoveries of Mr.
Turner and Mr. W. Borrer. The flowers
of Mosses, long neglected and afterwards
mistaken, were faithfully delineated by Mi-
cheli, carefully examined and properly un-
derstood by Linnaeus as he rambled over the
wilds of Lapland *, and at length fully illus-
trated and placed out of all uncertainty by
the justly celebrated Hedwig. These parts
indeed are still unknown in ferns, or at least
no satisfactory explanation of them has
readied me, though the seeds and seed-
vessels are sufficiently obvious.

* This hitherto unknown fact will appear in his Tour
through that country,- now preparing for the press in
English.

318 FUNCTIONS OP

The existence of the parts under considera-
tion is so incontrovertible in every flower
around us, that Pontedera was reduced to
seek plants without stamens among the fi-
gures of the Hortus Matabaricus, but the
plates in which he confided are now known
to be faulty in that very particular.

Plants indeed have occasionally abortive
stamens in one flower and barren pistils in
another, and the Plantain-tree, Musa> is de-
scribed by Linnaeus as having five out of its
six stamens perfected in such blossoms as
ripen no fruit, while those with a fertile ger-
men contain only a single ripe stamen, five
being ineffective. This only shews the re-
sources, the wisdom, .and the infinite variety
of the creation. When the roots are luxuri-
antly prolific, the flowers are in some mea-
sure defective, Nature, relaxing as it were
from her usual solicitude, and allowing her
children to repose, and indulge in the abun-
dance of good tlnngs about them.. But when
want threatens, she instantly takes the alarm;
all her energies are exerted to secure the fu-
ture progeny, even at the hazard of the pa-
rent stock, and to send them abroad to co-
lonise more favourable situations.

STAMENS AND PISTILS. . 319

Most generally the access of the pollen is
not trusted to any accidental modes of con-
veyance, however numerous, elaborate, and,
if we may so express it, ingenious, such modes
may be; but the Stamens are for greater se-
curity lodged in the same flower, under the
protection of the same silken veils, or more
substantial guards, which shelter their ap-
propriate pistils. This is the case with the
majority of our herbs and shrubs, and even
tyith the trees of hot countries, v/hose leaves
being always present might impede the pas-
sage of the pollen. On the contrary, the
trees cf cold climates have generally sepa-
rated flowers, blossoming before the leaves
come forth, and in a windy season of the
year ; while those which blossom later, as the
Oak, are either peculiarly frequented by in-
sects, or, like the numerous kinds of Fir, have
leaves so little in the way, and pollen so ex-
cessively abundant, that impregnation can
scarcely fail.

The pollen and the stigma are always in
perfection at the same time, the latter com-
monly withering and falling off a little after
the anthers, though the style may remain
to become an useful appendage to the fruit

320 FUNCTIONS OF*

The Viola tricolor or Pansy, the Gratiola.
the MartymG) and many plants besides, have
been observed to be furnished with a stigma
gaping only at the time the pollen is ripe.
The beautiful Jacobean Lity, Amaryllis
formosissima, Curt. Mag. i. 47? is justly de-
scribed by Linnaeus as provided with a drop
of clear liquid, winch protrudes every morn-
ing from the stigma, and about noon seems
almost ready to fall to the ground. It is
however reabsorbed in the afternoon, having
received the pollen whose vapour renders it
turbid, and whose minute husks afterwards
remain upon the stigma. The same phamo-r
menon takes place several successive days.

In opposition to similar facts, proving the
synchronous operation of these organs, Ponte-
dera has, with more observation than usual,
remarked that in the umbelliferous tribe the
style frequently does not appear till the an-
thers are fallen. But he ought to have per-
ceived tbat the stigma is previously perfected,
and that the style seems to grow out after-
wards, in a recurved and divaricated form,
for the purpose of providing hooks to the
seeds. It is al^o observable that in this fa-
mily the several .organs are sometimes brought

STAMENS AND PISTILS. 321

to perfection in different flowers at different
times, so that the anthers of one may im-
pregnate the stigmas of another, whose sta-
mens were abortive, or long since withered.
The same thing happens in other instances.
Linnieus mentions the Jatropha iirens as
producing flowers with stamens some weeks
in oreneral before or after the others. Hence
he k obtained no seed till he preserved the pol-
len a month or more in paper, and scattered
it on a few stigmas then in perfection. There
can be no doubt that, in a wild state, some
or other of the two kinds of blossoms are
ripe together, throughout the flowering sea-
son, on different trees.

A similar experiment to that just men-
tioned was made in 1749 upon a Palm-tree
at Berlin, which for want of pollen had never
brought any fruit to perfection. A branch
of barren flowers was sent by the post from
Leipsic, twenty German miles distant, and
suspended over the pistils. Consequently
abundance of fruit was ripened, and many
young plants raised from the seeds *.

* What species of Palm was the subject of this ex-
periment does not clearly appear. In the original com-

X

322 FACTIONS OP

Tournefort and Pontedera supposed the
pollen to be of an excrementkious nature,
and thrown off as superfluous. But its being
so curiously and distinctly organized in every
plant, and producing a peculiar vapour on
the accession of moisture, shows, beyond
contradiction, that it has functions to per-
form after it has left the anther. The same
writers conceived that the stamens might
possibly secrete something to circulate from
them to the young seeds ; an hypothesis to-
tally subverted by every flower with sepa-
rated organs, whose stamens could circulate
nothing to germens on a different branch or
root; a difficulty which the judicious Tourne-
fort perceived, and was candid enough to
allow.

munication to Dr. Watson, 'printed in the preface of
Lee's Introduction to Botany, it is called Palma major
folllsjialeUijormlbus, which seems appropriate to Rkapis
JlahelliformiS) Alt. Hort. Kew. v. 3. 473 j yet Linnaeus*
in his Dissertation on this subject, expressly calls it
Phoenix dactylifere, the Date Palm, and says he had in
his srarden many vigorous plants raised from a portion
of th« seeds above mentioned. The great success of the
experiment, and the u fan-shaped" leaves, make me ra-
ther take it tor the Rhapls, a plant not well known to
Linnaeus-,

STAMENS AND PISTILS. 323

m

Both the conjectures just mentioned vanish
before one luminous experiment of Linmeus,
of all others the most easy to repeat and t©
understand. He removed the anthers from
a flower of Glaucium phamicium ; Engl. Bot.
t. 1433, stripping off the rest of that day's
blossoms. Another morning he repeated the
same practice, only sprinkling the stigma of
that blossom, which he had last deprived of
its own stamens, with the pollen from an-
other. The flower first mutilated produced
no fruit, but the second afforded very perfect
seed. " My design," says Linnaeus, " was
to prevent any one in future from believing
that the removal of the anthers from a flower
was in itself capable of rendering the germen
abortive/'

The usual proportion and situation of sta-
mens with respect to pistils is well worthy of
notice. The former are generally shortest in
drooping flowers, longest in erect ones. The
barren blossoms stand above the fertile ones
in Car ex, Coix, Ricinus, Arum, &c, that
the pollen may fall on the stigmas. This is
the more remarkable, as the usual order cf
Nature seems in such plants, as well indeed
y 2

324 FUNCTIONS OF STAMENS AND PISTILS,

as in compound, and even umbelliferous
flowers, to be reversed, for the pistils are in-
variablv central, or internal, in every simple
flower, and would therefore, if drawn out
into a monoecious spike, be above the sta-
mens.

Many curious contrivances of Nature serve
to bring the anthers and stigmas together.
In Gloriosa, Andr. Repos. t. 129, the style
is bent, at a right angle from the very base,
for this evident purpose. In Saxifraga, and
Parnassia, Engl. Bot. t. 82, the stamens
lean one or two at a time over the stigma,
retiring after they have shed their pollen, and
giving place to others ; which wonderful oeco-
nomy is very striking in the garden Rue,
Rut a gravaolens, whose stout and firm fila-
ments cannot be disturbed from the posture
in which they may happen to be, and evince
a spontaneous movement unaffected by ex-
ternal causes. The five filaments of the
Celosia^ CockWomb, are connected at their
lower part by a membranous web, which in
moist weather is relaxed, and the stamens
spread for shelter under the concave lobes of
the corolla. When the air is dry the con-

IRRITABLE PARTS OF FLOWERS. 325

traction of the membrane brine's them toge-
ther, to scatter their pollen in the centre of
the flower. The elastic filaments of Parie-
taria, Engl. Hot. t. 8/9, for a while re-
strained by the calyx, as those of the lovely
Kalmice, Curt. Mag. t. 17 5, 1?7, are by
the minute pouches in the corolla, relieve
themselves by an elastic spring, which in
both instances serves to dash the pollen with
great force upon the stigma. The same end
is accomplished by the carved germen of
Medicago falcata, Engl. Hot. t. 1016, re-
leasing itself by a spring from the closed
keel of the flower.

But of all flowers that of the Barberry*
bush, t. 49, is most worthy the attention of
a curious physiologist. In this the six sta-
mens, spreading moderately, are sheltered
under the concave tips of the petals, till some
extraneous body, as the feet or trunk of an
insect in search of honey, touches the inner
part of each filament near the bottom. The
irritability of that part is such, that the fila-
ment immediately contracts there, and con-
sequently strikes its anther, full of pollen,
against the stigma. Any other part of the

320 ■ OF THE BARBERRY.

filament may be touched without this effect,
provided no concussion be given to the whole-
After a while the filament retires gradually,
and may again be stimulated ; and when each
petal, with its annexed filament, is fallen to
the ground, the latter on being touched
ghowg as much sensibility as ever. See Tracts
on Nat. History, l6o. I have never de-
tected any sympathy between the filaments,
nor is any thing of the kind expressed in the
paper just mentioned, though Dr. Darwin,
from some unaccountable misapprehension,
has quoted me to that effect. It is still more
wonderful that the celebrated Bonnet, as
mentioned in Senebier's Physiologic Vegttak,
z\ 5. 105, should have observed this phenome-
non in the Barberry so very inaccurately as to
compare it to the relaxation of a spring, and
that the ingenious Senebier himself, in quot-
ing me, p. 103, for having ascertained the
lower part only of each filament to be irrita-
ble, should express himself as follows : — " It
has not yet been proved that the movement
of the stamens is attended with the contrac-
tion of the filaments ; which nevertheless was
the first proof necessary to have been g;iven

OF THE BARBERRY. 327

in order to ascertain their irritability ; it is
not even yet well known which is the irritable
part of the filaments, and whether it be only
their base, as Smith has had the address to
discover/' In answer to which I need only
request any one to read the above account,
or the more ample detail in my original pa-
per, and above all, to examine a Barberry-
blossom for himself; and if any doubts re-
main concerning the existence of vegetable
irritability, let him read Senebier's whole
chapter intended to disprove it, where that
candid philosopher, while he expresses his
own doubts, has brought together every thing
in its favour. Among the whole of his facts
nothing is more decisive than the remarks of
Coulomb and Van Marum on the Euphorbia,
whose milky juices flow so copiously from a
wound, in consequence of the evident irrita-
bility of their vessels ; but when the life of
the plant is destroyed by electricity, all the
flowing is at an end. It is superfluous to add
any thing on this subject, and I return to
that of the impregnation of flowers.

I have already mentioned that any mois-
ture causes the, pollen to explode, conse-

32S PROTECTION OF THE POLLEN.

quently its purpose is liable to be frustrated
by rain or heavy dews. Linnaeus observes
that husbandmen find their crops of rye to
suffer more from this cause than barley, be-
cause in the latter the anthers are more pro-
tected by the husks ; and that Juniper berries
are sparingly, or not at all, produced in Swe-
den when the flowering season has been wet.
The same great observer also remarks, what
yearly experience confirms, that Cherry-trees
are more certainly, fruitful than Pear-trees,
because in the former the opening of the an-
thers is, in each blossom, much more pro-
gressive, so that a longer period elapses for
the accomplishment of the fertilization of the
germen, and there is consequently less chance
of its being hindered by a few showers.

To guard against the hurtful influence of
nocturnal dews or drenching rains, most
flowers either fold their petals together, or
hang down their heads, when the sun does
not shine ; by which, their internal organs
are sheltered. In some which always droop,
as the Snowdrops Galantkus and Leucojum,
Engl Bot. 1. 19 and 621, the Fritillary, t.6%%
the Crown Imperial, various species of Cam-

PROTECTION OF THE POLLEN, 32$

panula, and others, while the over-shad ow-
ing corolla keeps off rain, the air has free ac-
cess underneath to blow the pollen to the
stigma. Nor is this drooping caused by the
weight of the flowers, for the fruit in most
of them is much heavier, and yet stands
erect on the very same stalk. The papi-
lionaceous flowers in general spread their
wings in fine weather, admitting the sun and
air to the parts within ; whereas many of
them not only close their petals at night, but
also derive additional protection from the
green leaves of the plant folding closely about
them. Convolvulus arvensis, t. 312, Ana-
gallis arvensh, t* 529, Calendula pluvialis,
and many others, are well known to shut iu>
their flowers against the approach of rain;
whence the AnagalUs has been called the
Poor Man's Weather-glass. It has been ob-
served by Linnaeus that flowers lose this fine
sensibility, either after the anthers have per-
formed their office, or when deprived of them
artificially ; nor do I doubt the fact. I have
had reason to think that, during a long con-
tinuance of wet, the sensibility of the Ana-
gallis is sometimes exhausted ; and it is evi-

S30 EXPEDIENTS OS? HEMP,

dent that very sudden thunder-showers often
take such flowers by surprise, the previous
state of the atmosphere not having been such
as to give them due warning.

That parts of vegetables not only lose
their irritability, but even their vital princi-
ple, in consequence of having accomplished
the ends of their being, appears from an ex-
periment of Linnaeus upon Hemp. This is a
dioecious plant, see p. 306', and Linnaeus kept
several fertile-flowered individuals in sepa-
rate apartments from the barren ones, in
Order to try whether they could perfect their
seeds without the aid of pollen. Some few
however remained with the barren-flowered
plants, and these ripened seed in due time,
their stigmas having faded and withered soon
after they had received the pollen. On the
contrary, the stigmas which had been out of
its reach continued green and vigorous, as if
in vain expectation, nor did they begin to
fade till they had thus lasted for a very long
while. Since I read the history cf this expe-
riment, I have found it easy in many plants to
tell by the appearance of the stigma whether
the seed be fertilized or not. The above ex-

MELONS, CYCAS, &C. 33*

periment is the more important, as the abbe
Spallanzani has recorded one made by him-
self upon the same species of plant, with a
contrary result. But as he has said nothing
of the appearance of the stigmas, his expe-
riment must yield to that of Linnseus in
point of accuracy ; and even if his account
be otherwise correct, the result is easily ex-
plained. Hemp, Spinach, some Nettles, &c,
naturally dioecious, are occasional^ not com-
pletely so, a few latent barren or fertile
flowers being frequently found among those
of the other sort, by which provision is made
against accidents, and the perfecting of a few
seeds, at any rate, secured;

In general, germens whose stigmas have
not received the pollen wither away without
swelling at all, but some grow to a considera-
ble size, and in such the substance of the
seed, its skin, and even its cotyledons, are
often to be found, the embryo only being
wanting. In a Melon or Cucumber it is
common to find, among numerous perfect
seeds, many mere unimpregnated husks. In
the magnificent Cycas revoiuta which bore
fruit at the bishop of Winchester's, and of

332 (ECONOMY OF AGUATJC PLANTS.

which a history with plates is given in the
sixth volume of the Linnasan Society's Trans-
actions, I found the drupa and all its con-
tents apparently perfect, except that there
was only a minute cavity where the embryo
shuld have been, in consequence of the
w r ant of another tree with stamens, which was
not to be found perhaps nearer than Japan.
Gardeners formerly attempted to assist Na-
ture by stripping off the barren flowers of
Melons and Cucumbers, which, having no
germen, they found could not come to fruit,
and were therefore, as they supposed, an unr
. sary encumbrance to the constitution of
trent plant. But finding they thus ob-
tained no fruit at all, they soon learned the
wiser practice of admitting air as often as pos-
sible to the flowering plants, for the purpose of
blowing the pollen from one blossom to the
other, and even to gather the barren kind and
place it over that destined to bear fruit.

The ceconorny of various aquatic plants
throws great light upon the subject before us.
Different species of Pot amogetcn, Engl. Bot.
i. 168, 297, 376, &c, Ruppia maritirna,
f. 136, and others, float entirely under wa-

OF THE NYMPHJEA. 333

ter, often at some considerable depth, till
the flowering season arrives, when they rise
near the surface, and throw up their flower-
ing spikes above it, sinking afterwards to
ripen and sow their seeds at the bottom.
Nymphaa alba, t. 160, is very truly de-
scribed by Linnaeus in his Flora Siiecica,
as closing its flowers in the afternoon and
laying them down upon the surface of the
water till morning, when it raises and ex-
pands them, often, in a bright day, to se-
veral inches above the water. To this I can
speak from my own knowledge, and it is
confirmed by the history given by Theo-
phrastus of his Lotus, which, according to
all appearance, is the Nymphcva Lotas of
Linnsuus. " This," says he, " as well as the
Cyamus*, bears its fruit in a head. The
flower is white, consisting of many crowded
leaves about as broad as those of a lily.
These leaves at sunset fold themselves toge-
ther, covering the head (or seed-vessel). At
sun-rise they expand, and rise above the wa-
ter. This they continue till the head is per-
fected, and the flowers fall off." So far

* Exot. Bot. t. 31, 32.

334 OF THE NYMPH-EJU

: phrastus writes as of his own know-
% e ; he continues as follows : u It is re-
ported that in the Euphrates the head and
flowers keep sinking till midnight, when they
are so deep in the water as to be out of reach
of the hand, but towards morning they re-
turn, and still more as the day advances. At
sun-rise they are already above the surface,
with the flower expanded ; afterwards they
rise high above the water." Pliny repeats
the same account, and Prosper Alpinus, whose
purpose is to prove the Lotus of Theophrastus
not different from the common Nymphcm, in
which, as far as genus is concerned, he is
correct, has the following remarkable passage:
" The celebrated stories of the Lotus turning
to the sun, closing its flowers and sinking
under water at night, and rising again in the
morning, are conformable to what every body
has observed in the ISymphcea"

I have been the more particular in the
above quotations, because the veracity of
Theophrastus has lately been somewhat rudely
impeached, on very questionable authority.
For my own part, I think' what we see of the
Nymphcsa in England is sufficient to render

OF THE VALISNERIA. 335

the above account highly probable in a coun-
try where the sun has so much more power,
even if it did not come from the most faith-
ful and philosophical 'botanist .of antiquity,
and I have always with confidence cited it on
his authority. The reader, however, will per-
ceive that the only important circumstance
for our purpose is the closing of the flowers
at night, which is sufficiently well established.
But the most memorable of aquatic plants
is the Valisneria spiralis, well figured and
described by Micheli, Nov. Gen, t. 10, which
grows at the bottoms of ditches in Italy. In
this the fertile flowers stand on long spiral
stalks, and these by uncoiling elevate them
to the surface of the water, where the calyx
expands in the open air. In the mean while
plenty of barren flowers are produced on a
distinct root, on short straight stalks, from
which they rise like little separate white bub-
bles, suddenly expanding when they reach
the surface, and floating about in such abun-
dance as to cover it entirely. Thus their pol-
len is scattered over the stigmas of the first-
mentioned blossoms, whose stalks soon after-
wards resume their spiral figure, and &e

3

iSISTANCE OF INSECTS IN IMPREGNATtOV,

fiftut comes to maturity at the bottom of the
water. All this Micheli has described, with-
out being aware of its final purpose; so dif-
ferent is it to observe and to reason !

Some aquatic vegetables, which blossom
under water, seem to have a peculiar kind of
glutinous pollen, destined to perform its of-
fice in that situation, as Chara, Engl. Bot.
L 336, &c; as well as the Fucus and Con*
fcrva tribe : but of the real nature of the
fructification of these last we can at present
cnly form analogical conjectures.

The fertilization of the Fig is accomplished
in a striking manner by insects, as is that of
the real Sycomore, Ficus Sycomorus. In this
semis the green fruit is a hollow common
calyx, or rather receptacle, lined with vari-
ous flowers, seldom both barren and fertile
in the same fig. This receptacle has only
a very small orifice at the summit. The
seeds therefore would not in general be per-
fected, were it not for certain minute flies of
the genus Cynips, continually fluttering from
one fig to the other all covered with pollen,
and depositing their eggs within the cavity.

A verv curious observation is recorded by

ASSISTANCE OF INSECTS IN IMPREGNATION. 33?

Professor Willdenow concerning the Aristo-
lochia Ckmatitis, Engl Bot. t. 398. The
stamens and pistils of this flower are enclosed
in its globular base, the anthers being under
the stigma, and by no means commocliously
situated for conveying their pollen to it.
This therefore is accomplished by an insect,
the Tipula pennicomis, which enters the
flbwer by the tubular part. But that part
being thickly lined with inflexed hairs, though
the fly enters easily, its return is totally im-
peded, till the corolla fades, when the hairs
lie flat against the sides, and allow the carj-
tive to escape. In the mean while the insect,
continually struggling for liberty, and pacing
his prison round and round, has brushed the
pollen about the stigma. I do not doubt the
accuracy of this account, though I have ne-
ver caught the imprisoned Tipula. Indeed
I have never seen any fruit formed by this
plant. Probably for want of some insect
adapted to the same purpose in its own coun-
try, the American A rktolochia Sipho, though
it flowers plentifully, never forms fruit in our
gardens.

z

33S ASSISTANCE OF INSECTS IN IMPREGNATION.

The ways in which insects serve the same
purpose are innumerable. These active little
beings are peculiarly busy about flowers in
bright sunny weather, when every blossom
is expanded, the pollen in perfection, and all
the powers of vegetation in their greatest
vigour. Then we see the rousjh sides and
legs of the bee, laden with the golden dust,
which it shakes off, and collects anew, in its
visits to the honeyed stores which invite it on
every side. All Nature is then alive, and a
thousand wise ends are accomplished by in-
numerable means that " seeing we perceive
not " for though in the abundance of crea-
tion there seems to be a waste, yet in pro-
portion as we understand the subject, we find
the more reason to conclude that nothing is
made in vain.

339

CHAPTER XXL

ON THE DISEASES OF PLANTS, PARTICLE
1 LARLY AS ILLUSTRATIVE OF THEIR
VITAL PRINCIPLE*

The diseases of Vegetables serve in many
instances to prove their vitality, and to illus-
trate the nature of their constitution.

Plants are subject to Gangrene or Sphace-*
his, especially the more succulent kinds, of
which a very curious account, concerning the
Cactus coccinellifer, Indian Fig, or Nopal,
extremely to our present purpose, is given by
M. Thiery de Menonville, in bis work on the
culture of the Nopal as the food of the Cochi-
neal insect. This writer travelled, about 20
years since, through the Spanish settlements
in South America, chiefly noted for the culti-
vation of this precious insect, on purpose to
transport it clandestinely to gome of the
% %

340 GANGRENE OF PLANTS.

French islands. Such were the supineness
and ignorance of the Spaniards, that he suc-
ceeded in conveying, not only the living in-
sects, but the bulky plant necessary for their
sustenance, notwithstanding severe edicts to
the contrary. He had attended previously to
the management of the Nopal, and made his
remarks on the diseases to which it is liable.
Of these the Gangrene is extremely frequent
in the true Nopal of Mexico, beginning by a.
black spot, which spreads till the whole leaf
or branch rots off, or the shrub dies. But
the same kind of plant is often affected with
a much more serious disease, called by Thiery
" la dissolution" This seems to be a sudden
decay of the vital principle, like that pro-
duced in animals by lightning or strong elec-
tricity. In an hour's time, from some un-
known cause, a joint, a whole branch, or
sometimes an entire plant of the Nopal,
changes from apparent health to a state of
putrefaction or dissolution. One minute its
surface is verdant and shining; the next it
turns yellow, and all its brilliancy is gone.
On cutting into its substance, the inside is
found to have lost all cohesion, being quite

FALL OF THE LEAF. 341

rotten. The only remedy in this case is
speedy amputation below the diseased part.
Sometimes the force of the vital principle
makes a stand, as it were, against the en-
croaching disease, and throws off the infected
joint or branch. Such is the account given
by Thiery, which evinces a power in vege-
tables precisely adequate to that of the ani-
inal constitution, by which an injured or dis-
eased part is, by an effort of Nature, thrown
off to preserve the rest.

Nor need we travel to Mexico to find ex-
amples of this. Every deciduous tree or
shrub exhibits the very same phenomenon ;
for the fall of their decaying foliage in au-
tumn, leaving the branches and young buds
vigorous and healthy, can be explained in no
other way. Yet Du Hamel laboured in vain
to account for the fall of the leaf* ; nor is it
wonderful that he or any body else, who en-
deavours to explain the physiology of vege-
tables or of animals according to one prin-
ciple only, whether it be mechanical or che-
mical, should entirely fail. To consider the
fall of leaves in autumn as a sloughing, or

* See his Phys. des Arhres, v. l r 127.

342 FALL OF THE LEAtf

casting ofif diseased or worn out parts, seems
so simple and evident, as to be hardly worth
insisting upon. Yet I find myself antici-
pated in this theory by one physiologist only,
named Vrolick, cited by Willdenow, in his
Principles of Botany, p» 304, though several
learned speculations to no purpose are extant
on the subject. It is but just, however, that
I should relate what led me to consider the
matter with any attention. My observing
friend Mr. Fairbairn of Chelsea garden long
aoo remarked to me, that when he had occa-
sion to transplant any tree or shrub whilst
in leaf, he could soon judge of its success by
the ease with which its leaves were detached.
The consequence of such treatment is more
or less injury to the health of the plant, as
will first appear by the drooping of the leaves,
most of which will probably die, and the de-
cay will generally be extended to the younger
more delicate twigs. The exact progress of
this decay may speedily be known, by the
leaves of those branches which are irrecover-
ably djing or dead, remaining firmly at-
tached, so as not to be p<nicd ofT without a
force sufficient to bring away the bark or

AND OF HIPE FRUIT. 343

buds along with them : whereas the leaves
of parts that have received no material injury,
and where the vital energy acts with due
power, either fall off spontaneously, or are
detached by the slightest touch. Plants of
hot countries, kept in our stoves, exhibit the
same phenomenon when transplanted or
otherwise injured, even though not naturally
deciduous.

So when fruits are thoroughly ripened, they
become, with respect to the parent plant,
dead substances, and, however strongly at-
tached before, are then thrown off as extra-
neous bodies. Their stalks fade or wi-
ther, though the life of the adjoining branch
continues unimpaired, and a line of separa-
tion is soon drawn. In a poor soil, or unfa-
vourable climate, a bunch or spike which
should naturally consist of a considerable
number of flowers, bears perhaps not half so
many. Its upper part very early withers,
the vital principle ceases to act at the point
beyond which it could not continue to act
with effect, and all its energy is directed to
perfect what lies within the compass of its
>'; sources. This is evident in L(itlwrus o<lu-

344 OF GALLS AND

rat us, the Sweet Pea of our gardens, a native
of a very hot climate, at the summits of
whose flower-stalks are generally found the
rudiments of one or more flowers, not at-
tempted to be perfected. So also the first
Barley sown on the sandy heaths of Norfolk,
and indeed too many a following crop, bears
very few grains in an ear ; for the same
meagre supply of nourishment, bestowed
equally on a numerous spike of blossoms,
would infallibly starve them all. In like
manner one seed only is perfected in the
best wild Arabian Coffee, known by its round
form ; while the West Indian plantation Cof-
fee has two in each berry, both consequently-
flattened on one side. The former grows in
barren open places, in situations sufficiently
favourable for the impregnation of its blos-
soms, but far less so for the perfecting of
much seed; while the latter, well supplied
with manure and moisture, is enabled to
bring every germ to maturity. C

Very strange effects are often produced
upon plants by the attacks of insects, whence
the various kinds of Galls derive their origin.
These are occasioned by the punctures of

VARIOUS EXCRESCENCES. 343

those little animals, chiefly of the Ilymaw-
ptera order, and of the genus Cynips^ in
some vigorous part of the plant, as the leaves,
leaf-stalks, young stem or branches, and
sometimes the calyx or germen. The parent
insect deposits its egg there, which is soon
hatched, and in consequence of the perpetual
irritation occasioned by the young maggot,
feeding on the juices of the plant, the part
where it is lodged acquires a morbid degree
of luxuriance, frequently swelling to an im-
moderate size, and assuming the most extra-
ordinary and whimsical shapes. This often
happens to the shrubby species of Hawkweed,
Mieracium sabaudim, Engl. Bot« /.349? and
vmbellaiiim, t. 1771? whose stems in conse-
quence swell into oval knots. Several different
kinds of Galls are borne by the Oak, as those
light spongy bodies, as big as walnuts, vulgarly
named Oak apples ; a red juicy berry-like
excrescence on its leaves ; and the very as-
tringent Galls brought from the Levant, for
the purposes of dyeing and making ink, which
last are produced by a different species of
Querc >s from either of our own. The com-
mon Dog-rose, t. 992, frequently bears large

346 REMARKABLE EXCRESCENCES.

moss-like bails, in whose internal parts nu-
merous maggots are always to be found, till
they become the winged Cynips lias a, and
eat their way out. Many of our Willows
bear round excrescences, as large as peas, on
their leaves ; but I remember to have been
very much astonished in Provence with a
fine branched production on the Willows in
winter, which appeared like a tufted Lichen,
but proved on examination a real Gall. In-
deed our Saliz Helix, t. 1343, is called Rose,
Willow from its bearing no less remarkable
an excrescence, like a rose, at the ends of
some of its branches, in consequence of the
puncture of an insect, and thesn are in like
manner durable though the proper leaves fall.
The Mastic-tree, Pistacia Lentiscus, is often
laden, in the south of Europe, with large red
hollow finger-like bodies, swarming internally
with small insects, the Aphis Vistacice of
Linnaeus. The young shoots of Salvia po-
mifera, Fl. Grctc. t. 15, S. triloba, t. 17,
and even S. officinalis, in consequence of the
attacks probably of some Cynips, swell into
large juicy balls, very like apples, and even
crowned with rudiments of leaves resembling

DISEASES OF THE SKIN, W

the calyx of that fruit. These are esteemed
in the Levant for their aromatic and acid
flavour, especially vvhen prepared with sugar.
It may be remarked that all the excres-
cences above mentioned are generally more
acid than the rest of the plant that boars
them, and also greatly inclined to turn red.
The acid they contain is partly acetous, but
more of the astringent kind.

The diseases of the skin, to which many
vegetables are subject, are less easily under-
stood than the foregoing. Besides one kind
of Honey-dew, already mentioned p. 189,
something like leprosy may be observed in
Tragopogon major, J acq. Austr. t. 29, which,
as I have been informed by an accurate ob-
server, does not injure the seed, nor infect
the progeny. The stem of Shepherd's Purse,
Engl. Bot. t. 1485, is occasionally swelled,
and a white cream-like crust, afterwards
powdery, ensues. The White Garden Rose,
Rosa alba, produces, in like manner, an
orange-coloured powder. It proves very dif-
ficult, in many cases, to judge whether such
appearances proceed from a primary disease
in the plant, arising from unseasonable cold

348 OF THE BLIGHT AND

or wet, or are owing to the baneful stimulus
of parasitical fungi irritating the vital prin-
ciple, like the young progeny of insects as
above related. Sir Joseph Banks has, with
great core and sagacity, traced the progress
of the Blight in Corn, Uredo frummtij
Soz&erk Fung. t. 140, and given a complete
history of the minute fungus which causes
that appearance. See Annals of Botany,
v. 2. SI, ^.3, 4. Under the inspection of
this eminent promoter of science, Mr. Francis
Bauer has made microscopical drawings of
many similar fungi infecting the herbage
and seeds of several plants, but has decided
that the black swelling of the seed of corn,
called by the French Ergot, though not well
distinguished from ether appearances by the
generality of our agricultural writers, is indu-
bitably a morbid swelling of the seed, and
not in any way connected with the growth of
a fungus. The anthers of certain plants often
exhibit a similar disease, swelling, and pro-
ducing an inordinate quantity of dark pur-
plish powder instead of true pollen, as hap-
pens in Silene inflata, Fl. Brit. Engl. Bot.
t, 164, and the white Lychnis clioica, t. 1580,

SIMILAR DISEASES. 349

whose petals are, not uncommonly, stained
all over with this powder. Our knowledge on
all these subjects is yet in its infancy ; but it
is to be hoped, now the pursuit of agriculture
and of philosophical botany begin to be, in
some distinguished instances, united, such
examples will be followed, and science di-
rected to one of its best ends, that of im-
proving useful arts. And here I cannot but
mention the experiments continually going on
under the inspection of the ingenious Mr.
Knight, of fertilizing the germen of one spe-
cies or variety with the pollen of another
nearly akin, as in apples, garden peas, &c,
by which, judiciously managed, the advan-
tages of different kinds are combined. By
the same means Linnaeus obtained interme-
diate species or varieties of several plants ;
and if any thing were wanting to confirm his
theory respecting the stamens and pistils, this
alone would place it out of all uncertainty.

3:>o

CHAPTER XXII.

OF THE SYSTEMATICAL ARRANGEMENT
OF PLANTS. NATURAL AND ARTIFI-
CIAL METHODS. GENERA, SPECIES AND
VARIETIES. NOMENCLATURE.

The foregoing chapters have sufficiently ex-
plained the parts of plants, and the leading
differences in their conformation, for us now
to proceed to the Systematical part of our
subject. In this, when properly understood
and studied, there is no less exercise for the
mind, no less employment for its observation
and admiration, than in physiological or ana-
tomical inquiries ; nor are the organs of ve-
getables, when considered only as instru-
ments of classification and discrimination, lest
conspicuous for beauty, fitness, and infinite
variety of contrivance, than under any other
point, of view. The wisdom of an Infinite

OF BOTANICAL ARRANGEMENT. 351

Superintending Mind is displayed throughout
Nature, in whatever way we contemplate her
productions.

When we take into consideration the mul-
titude of species which compose the vegetable
kingdom, even in any one country or climate,
it is obvious that some arrangement, some
regular mode of naming and distinguishing
them, must be very desirable, and even ne-
cessary, for retaining them in our own me-
mory, or for communicating to others any
thing concerning them. Yet the antients
have scarcely used any further classification
of plants than the vague and superficial divi-
sion into trees, shrubs and herbs, except a
consideration of their places of growth, and
also of their qualities. The earlier botanists
anions; the moderns almost inevitably fell
into some rude arrangement of the objects of
their study, and distributed them under the
heads of Grasses, Bulbous plants, Medicinal
or Eatable plants, &c, in which their suc-
cessors made several improvements, but it is
not worth while to contemplate them.

The science of Botanical Arrangement first
assumed a regular form under the auspices of
Conrad Gesner and Csesalpinus, who, inde-

352 METHODS OP C^SALPINUS,

pendent of each other, without any mutual
communication, both conceived the idea of a
regular classification of plants, by means of
the parts of fructification alone, to which the
very existence of Botany as a science is
owing- The first of these has left us scat-
tered hints only, in various letters, commu-
nicated to the world after his premature death
in 1565 ; the latter published a system,
founded on the fruit, except the primary di-
vision into trees and herbs, in a quarto vo-
lume printed at Florence in 1583. This
work Linnaeus studied with great care, as ap-
pears from the many notes and marked pas-
sages in his own copy now before me. Hence
he adopted his ideas of the supposed origin
of the calyx, corolla, stamens, and pistils,
from the outer bark, inner bark, wood and
pith, which are now r proved to be erroneous.
In his own Classes Plant arum he has drawn
out a regular plan of the System of Cresalpinus,
the chief principles of which are the following :

1. Whether the embryo be at the summit or
base of the seed.

2. Whether the germen be superior or in-
ferior.

rivinus, kuppius, 8tc. 353

3. Seeds 1, 2, 3, 4, or numeroas.

4. S^ed^vessels .1, 2, 3, 4, &c.

The work of Cesalpinus, though fall of in-
formation, was too deep to be of common
use, and excited but little attention. A cen-
tury afterwards M orison, Professor of Botany
at Oxfordj improved somewhat upon the ideas
of the last-mentioned writer, but has been
ju&tly blamed tor passing over in silence the
source or his own information. Ray, the
great English aaturalist, formed a consider-
ably different system upon the fruit, as did
Hemrmn, Professor at Leyden, and the great
Boerhaave, bat in these last there is little
originality*.

Rivinus, Ruppius and Ludwig in Germany
proposed to arrange plants by the various
forms of their Corolla, as did Tournefort the
illustrious French botanist, whose; system is
by far the bt si the kind ; and this having
been mor^ celebrated than most others, J shall
give a sketch of its plan.

In the first place we meet with the old but
highly unphilospphical division into Herbs
and Trees, each of which sections is subdi-

2 a

354 METHODS OF TOURNEFORT,

vided into those with a Corolla and those
without. The Trees with a Corolla are again
distributed into such as have one or many
petals, and those regular or irregular. — Herbs
with a Corolla have that part either com-
pound (as the Dandelion, Thistle and Daisy),
or simple ; the latter being either of one or
many petals, and in either case regular or
irregular. We come at last to the final sec-
tions, or classes, of the Tournefortian system.
Herbs with a simple, monopetalous, regular
corolla are either bell-shaped or funnel-
shaped ; those with an irregular one either
anomalous or labiate.

Herbs with a simple, polypetalous, regular
corolla are either cruciform, rosaceous, um-
bellate, pink-like or liliaceous ; those with an
irregular one, papilionaceous or anomalous.
The subdivisions of the classes are founded
on the fruit.

It is easy to perceive that a system of this
kind can never provide for all the forms of
corolla which may be discovered after its
first contrivance ; and therefore the celebrated
Dr. Garden, who studied by it, assured me
that when he attempted to reduce the Arne-

MAGNOL AND LINN^US. 355

rican plants to Tournefort's classes, he found
them so untraceable, that, after attempting in
vain to correct or augment the system, he
should probably have given up the science
in despair, had not the works of Linnaeus
fallen in his way.

Magnol, Professor at Montpellier, and even
Linnaeus himself, formed schemes of arranging
plants by the calyx, which nobody has folio wedo

All preceding systems, and all controver-
sies respecting their superior merits, were
laid aside, as soon as the famous Linnaean
method of classification, founded on the Sta-
mens and Pistils, became known in the bo-
tanical world. Linnaeus, after proving these
organs to be the most essential of all to the
very being of a plant, first conceived the for-
tunate idea of rendering them subservient to
the purposes cf methodical arrangement,
taking into consideration their number, situ-
ation and proportion. How these principles
are applied, we shall presently explain ; but
some previous observations are necessary.

Linnaeus first made a distinction between
a natural and an artificial method of bo*
tanical arrangement. His predecessors pro-
2 a 2

356 OF A NATOKAL MODE

bably conceived their own systems to be
each most consonant with the order of Nature,
as well as most commodious for use, and it
was reserved for him to perceive and to ex-
plain that these were two very distinct things.
The most superficial observer must per-
ceive something of the classification of Na-
ture. The Grasses, Umbelliferous plants,
Mosses, Sea-weeds, Ferns, Liliaceous plants,
Orchises, Compound flowers, each constitute
a family strikingly similar in form and quali-
ties among themselves, and no less evidently
distinct from all others. If the whole vege-
table kingdom could with equal facility be
distributed into tribes or classes, the study of
Botany on such a plan would be no less easy
than satisfactory. But as we proceed in this
path, we soon find ourselves in a labyrinth.
The natural orders and families of plants, so
far from being connected in a regular series,
approach one anotfier by so many points, as
to bewilder instead of directing us. We may
seize some striking combinations and ana-
logies ; but the further we proceed, the more
we. become sensible that, even if we had the'
whole vegetable world before us at one view.

OF CLASSIFICATION. 357

our knowledge must be imperfect, and that
our " genius" is certainly not " equal to the
Majesty of Nature/' Nevertheless Linnaeus,
and all true philosophical botanists since the
first mention of the natural affinities of plants,
have ever considered them as the most im-
portant and interesting branch, or rather the
fundamental part, of systematical botany.
Without them the science is truly a study of
words, contributing nothing to enlarge, little
worthy to exercise, a rational mind. Lin-
naeus therefore su^o-ests a scheme which he

CO

modestly calls Fragments of a Natural Me-
thod, which formed the subject of his occa-
sional contemplation ; but he daily and hourly
studied the principles of natural affinities
among plants, conscious that no true know-
ledge of their distinctions, any more than of
their qualities, could be obtained without ; of
which important truth he was not only the
earliest, but ever the most strenuous assertor.
In the mean while, however, Linnaeus, well
aware that a natural classification was scarcely
ever to be completely discovered, and that if
discovered it would probably be too difficult
for common use, contrived an artificial sy-

3*58 LINN^EAN ARTIFICIAL METHOD,

stem, by which plants might conveniently be
arranged, like words in a dictionary, so as to
be most readily found. If all the words of a
language coula be disposed according to their
abstract derivations, or grammatical affinities,
such a performance mi^ht be very instructive
to a philosopher, but would prove of little
service to a young scholar ; nor has it ever
been mentioned as any objection to the use
of a dictionary, that words of very different
meanings, if formed of nearly the same letters,
often stand together. The Method of Lin-
naeus therefore is just such a dictionary in
Botany, while his Philosophia Botanica is
the grammar, and his other works contain
the history, and even the poetry, of the sci-
ence.

But before we give a detail of his artificial
system, we must first see how this great man
fixed the fundamental principles of botanical
science. Nor are these principles confined to
botany, though they originated in that study.
The Linnaean style of discriminating plants,
has been extended by himself and others to
animals and even fossils ; and his admirable
principles of nomenclature are applied with

DEFINITION OF SPECIES. 359

great advantage even to chemistry itself, now
become so vast and accurate a science.

Independently of all general methods of
classification, whether natural or artificial,
plants, as well as animals, are distinguished
into Genera*, Species, and Varieties.

By Species are understood so many indi-
viduals, or, among the generality of animals,
so 'many pairs, as are presumed to have been
formed at the creation, and have been perpe-
tuated ever since ; for though some animals
appear to have been exterminated, we have
no reason to suspect any new species has
been produced ; neither have we any cause
to suppose any species of plant has been lost,
nor any new one permanently established,
since their first formation, notwithstanding
the speculations of some philosophers. We
frequently indeed see new Varieties, by which
word is understood a variation in an esta-
blished species; but such are imperfectly, or

* Our scientific language in English is not sufficiently
perfect to afford a plural for genus, and we are therefore
obliged to adopt the Latin one, genera, though it exposes
us sometimes to the horrors of hearing of " a new ge-
nera' 1 of plants.

360 OP GENERA AND

for a limited time, if at all, perpetuated in
the offspring.

A Genus comprehends one or more spe-
cies, so essentially different in formation, na-
ture, and often many adventitious qualities,
from other plants, as to constitute a distinct
family or kind, no less permanent, and founded
in the immutable laws of the creation, than
the different species of such a genus. Thus
in the animal kingdom, a horse, ass and zebra
form three species of a very distinct genus,
marked, not only by its general habit or
aspect, its uses and qualities, but also by es-
sential characters in its teeth, hoofs, and in-
ternal constitution. The lion, tiger, leopard,
panther, lynx, cat, &c, also compose another
sufficiently obvious and natural genus, and
the numerous herd of monkeys, apes and ba-
boons a third. The elephant is, as far as we
know, a solitary species of a most distinct
and striking genus.

So among vegetables, the various species of
rose compose a beautiful genus, known to
every one who ever looked at a plant, merely
by a certain combination of ideas, but essen-^
tially distinguished, as we shall hereafter find 5

THEIR CHARACTERS. 361

bj>- clear and decisive characters. The spe-
cies of Iris form also a numerous genus, and
the Willows another ; while the curious Epi-
medmm alpinum^ Engl. Bot. t. 438, is too
singular and distinct to be associated with
any plant besides, and constitutes a genus by
itself, as well as the Adoxa, /. 453, and Lin-
naa, t. 433.

* The first great and successful attempt to
dehne the genera of plants was made by
Ton me fort, and in this his transcendent me-
rit will ever be conspicuous, though his sy-
stem or arrangement should ht entirety for-
gotten. Not that he has excelled m verbal
definitions, nor built all Iris genera on sure
foundations ; but his figures, and his enumera-
tions of species under each genus, show the
clearness of his conceptions, and rank him as
the father of this branch of botany.

Linnaeus first insisted on generic charac-
ters being exclusively taken from the 7 parts
of fructification, and he demonstrated these
to be sufficient for all the plants that can be
discovered. He also laid it down as a maxim,
that all genera are as much founded in na-
ture as the species which compose them; and

362 CHARACTERS

l

hence follows one of the most just and valu-
able of all his principles, that a genus should
furnish a character, not a character form a
genus ; or, in other words, that a certain co-
incidence of structure, habit, and perhaps
qualities, among a number of plants, should
strike the judgment of a botanist, before he
fixes on one or more technical characters, by
which to stamp and define such plants as one
natural genus. Thus the Hemerocallis cceru-
lea, Andr. Repos. t. 6, and alba, t. 194,
though hitherto referred by all botanists to
that genus, are so very different from the
other species in habit, that a discriminative
character might with confidence be expected
in some part or other of their fructification,
and such a character is accordingly found in
the winged seeds. Yet in the natural genera
of Arenaria and Spergula, winged or bor-
dered seeds are so far from indicating a di-
stinct genus, that it is doubtful whether they
are sufficient to constitute even a specific
character. See Engl. Bot. t. 958, 1535 and
1536. So Blandfordia, Exot. Bot. t. 4, is
well distinguished from Aletris, with which
some botanists have confounded it, by its

OP GENERA. 363

hairy seeds ; but the same circumstance will
not justify us in separating a few species from
Convolvulus, which are attached to that ge-
nus by stronger ties of another kind.

Some genera are obvious and indubitable
both in habit and character, as Quercns,
Rosa, Euphorbia, Begonia, Eiot. Bot. t. 101,
and Sarracenia, t. 53 ; others are obvious,
bitt their character extremely difficult to de-
fine, as Valeriana. The greatest difficulty
lies in distinguishing genera that belong to
such very natural orders as the Grasses
and Umbelliferous plants ; and the ablest
botanists differ about the best guides in these
two particular cases. Yet other orders,
equally natural, sometimes afford very ex-
cellent generic differences, as that to which
Rosa, Rubus, Fragaria, &c, belong ; and
even in the Papilionaceous plants with ten
distinct stamens, a tribe hitherto judged in-
extricable, a regular examination on scientific
principles has led to the discovery of very na-
tural well-defined genera. See Annals of
Botanij, v. 1. 501. I have in a preceding
chapter hinted that the umbelliferous plants

364 CHARACTERS

seem to me very capable of being well dis-
criminated by their seeds, and other botanists
have held the same opinion.

But though I feel convinced, as far as
my experience goes, that genera are really
founded in nature, I am far from asserting
that Linnseus, or any other writer, has suc-
ceeded in fixing all their just limits. This
deep and important branch of natural science
reo x uires the union of various talents. Many
persons who can perceive a genus cannot de-
fine it ; nor do acuteness of perception, so-
lidity of judgment, and perspicuity of ex-
pression, always meet in the same person.
Those who excel in this department are
named by Linnaeus, FhiL Bot. sect. 152,
theoretical botanists; those who -study only
species and varieties, practical ones.

In methodical arrangement, whether na-
tural or artificial, every thing must give way
to generic distinctions. A natural system
which should separate the species of a good
genus, would by that very test alone, prove
entirely worthless ; and if such a defect be
sometimes unavoidable in an artificial one,
contrivances must be adopted to remedy it,

OF GENERA. 36$

of which Lmnoeus has set us the example, as
will hereafter be explained.

Generic characters are reckoned by Lin-
naeus of three kinds, the factitious, the es-
sential, and the natural, ah founded on the
fructification alone, and not on the inflores-
cence, nor any other part.

The first of these serves only to discrimi-
nate genera that happen to come together in
the same artificial order or section ; the second
to distinguish a particular genus, by one
striking mark, from all of the same natural
order, and consequently from all other plants ;
and the third comprehends every possible
mark common to all the species of one
genus.

The factitious character can never stand
alone, but may sometimes, commodiously
enough, be added to more essential distinc-
tions, as the insertion of the petals in Agri-
monia, Engl. Hot. t. 1335, indicating the
natural order to which the plant belongs,
which character, though essential to that or-
der, here becomes factitious.

Linnaeus very much altered his notions of
the essential character after he had published

366 OP ESSENTIAL

his Vhilosophia Botanica, whence the above
definitions are taken. Instead of confining
it to one mark or idea, he, in his Systema
Vegetabilhim, makes it comprehend all the
distinctions requisite to discriminate each ge-
nus from every other in the system, only
avoiding a repetition at every step of the
characters of the artificial class and order,
which stand at the top of each page, and are
not always essential to the character of the
genus. This is the kind of generic character
now universally adopted, and indeed the only
one in common use. The learned Jussieu
has given it the sanction of his approbation
and adoption, as tar as its plan is concerned,
throughout his immortal work, subjoining in
a different type such characters and remarks
as belong to the habit, or refer to other cir-
cumstances. For my own part I profess to
retain, not only the plan, but the very words
of Linnceus, unless I find them erroneous,
copying nothing without examination, but
altering with a very sparing hand, and leav-
ing much for future examination. I cannot
blame my predecessors for implicitly copying
the Linnsean characters, nor should I have

GENERIC CHARACTERS. 367

been the first among English writers to set a
contrary example, had I not fortunately been
furnished with peculiar materials for the pur-
pose.

The beauty and perfection of these essen-
tial generic characters consist in perspicuity,
and a clear concise style of contrasting them
with each other. All feebleness, all super-
fluity, should be avoided by those who are
competent to the purpose, and those who are
not should decline the task. Comparative
words, as long or short, without any scale of
comparison, are among the grossest, though
most common, faults in such compositions.

The natural character seems to have been,
at one time, what Linnaeus most esteemed.
It is what he has used throughout his Genera
Plant arum, a work now superseded by the
essential characters in his Systema Vegeta-
biliam, and therefore in some measure laid
aside. The disadvantages of the natural cha-
racter are, that it does not particularly ex-
press, nor direct the mind to, the most im-
portant marks, and that it can accord only
with such species of the genus as are known
to the author, being therefore necessarily im-

SOB CONSTRUCTION CF

perfect. This kind of character is, however,
admirable for the illustration of any diiheuk
natural order. Mr. Gawler s elucidations of
the Ensata 9 Sword-leaved plants, Annals of
Botany, v. 1, 21& and Curt. Mag. afford
excellent specimens of it, serving as a store of
facts and observations for following systema-
tical writers.

Specific characters should be constructed
on similar principles to the generic ones, as
far as regards certainty, clearness and con-
ciseness. The genus being first well defined,
we are to seek for characters, not mentioned
among the generic marks, for distinguishing
the species. A specific difference for a soli-
tary soecies of any genus, is therefore an ab-
surdity. Linnoeus at first intended his spe-
cific definitions should be used as names ; but
t . invention of trivial names happily set
aside this inconvenient scheme. On this ac-
count however he - limited each to twelve
words, a rule to which all philosophical na-
turalists have adhered, except in cases of
great necessity. Nor is the admission of one
or two words beyond the allotted number re-
prehensible, provided the -whole sentence be

SPECIFIC CHARACTERS. 369

so neatly and perspicuously constructed, that
the mind may comprehend it, and compare
it with others, at one view ; but this can
hardly be done when the words much exceed
twelve. This rule, of course, can be strictly
applied to Latin definitions only, though it
should be kept in view in any language, as
far as the genius of that lan^uag-e will allow.
Linnaeus says, " Genuine specific distinctions
constitute the perfection of natural science ;"
which is strongly confirmed by the great in-
feriority of most botanists, in this depart-
ment, to that great man, and especially by
the tedious feebleness and insufficiency dis-
played among those who court celebrity by
despising his principles.

In constructing generic and specific cha-
racters, the arrangement of the different parts
on which they are founded is to be consider-
ed. Such as are most important in the na-
tural order, or genus, are to stand first, and
the subordinate, or more peculiar marks of
the object before us, ought to close the sen-
tence. On the contrary, in drawing up na-
tural characters of a genus, as well as full
descriptions of particular plants, it is proper
2 B

370 ' PRINCIPLES

to take, in the former instance, the calyx,
corolla, stamens, pistils, seed-vessel, seed
and receptacle, and in the latter, the root,
stem, leaves, appendages, flower and fruit,
in the order in which they naturally occur.

Nomenclature is no less essential a branch
of methodical science than characteristic de-
finitions ; for, unless some fixed laws, or, in
other words, good sense and perspicuity, be
attended to in this department, great con-
fusion and uncertainty must ensue.

The vague names of natural objects handed
down to us, in various languages, from all
antiquity, could have no uniformity of de-
rivation or plan in any of those languages.
Their different origins may be imagined, but
cannot be traced. Many of these, furnished
by the Greek or Latin, are retained as ge-
neric names in scientific botany, though nei-
ther their precise meaning, nor even the
plants to which they originally belonged, can
always be determined, as Piosa, Ficus, Pi-
per, &c. It is sufficient that those to which
they are now, by common consent, applied,
should be defined and fixed. Botanists of
the Linnaean school, however, admit no such

OF NOMENCLATURE. 371

generic names from any other language than
the Greek or Latin, all ethers being esteemed
barbarous. Without this rule we should be
overwhelmed, not only with a torrent of un-
couth and unmanageable words, but we should
be puzzled where to fix our choice, as the
same plant may have fifty different original
denominations in different parts of the world,
and we might happen to choose one by which
it is least known. Thus the celebrated In-
dian plant now proved beyond all doubt to
be the Cyamus of Theophrastus*,«. having
been erroneously reckoned by Linnaeus a
Nymphcea, received from Gaertner, one of
the first who well distinguished it as a genus,
the Ceylon name of Nelumbo ; which being;
contrary to all rules of science, literature or
taste for a generic name, has by others been
made into bad Latin as JSelumbium. But
the universal Hindu name of the plant is

* See Exot. Bot.v. 1. 60, where the arguments in
support of this opinion are given, and Curt. Mag. t. 903,
where some of them are with much candour and inge-
nuity controverted, though not so as to alter my senti-
ments ; nor can any thing justify the use of Nvlumlium
in a scientific work as a generic name.

2b2

372 OF BARBAROUS NAMES.

Tamard, which, independent of barbarism?
ought to have been preferred to the very con-
fined one of Nelumbo. In like manner the
Bamboo, Arundo Bambos of Linmjeus, prov-
ing a distinct genus, has received the appella-
tion of Bambusa, though J ussieu had already
given it that of Nastns from Dioscorides *.
Perhaps the barbarous name of some very
local plants, when they cannot possibly have
been known previously by any other, and
when that name is harmonious and easily re-
concileable to the Latin tongue, may be ad-
mitted, as that of the Japan shrub Aticaba;
but such a word as Ginkgo is intolerable.
The Roman writers* as Caesar, in describing
foreign countries, have occasionally latinized
some words or names that fell in their way,
which may possibly excuse our making
Ailanthns of Aylanto, or Pandanus of Pan-

* It is not indeed clear that this name is so correctly-
applied as that of Cyamus, because Nastus originally be-
longed to " a reed with a solid stern/' perhaps a palm ;
but not being wanted, nor capable of being correctly
used, for the latter, it may very well serve for the Bam-
boo. There is no end of raking up old uncertainties
about classical names,

GREEK OR LATIN NAMES. 3 73

dang. Still I can only barely tolerate such
names out of deference to the botanical me-
rits, not the learning, of their contrivers;
and I highly honour the zeal and correctness
of Mr. Salisbury, who, in defiance of all
undue authority, has ever opposed them,
naming Aucuba, on account of its singular
base or receptacle, Eubasis. I know not how
Pqndanus escaped his reforming hand, espe-?
cially as the plant has already a good cha-
racteristic Greek name in the classical Forster,
AthrodactijUs.

Excellent Greek or Latin names are such
as indicate some striking peculiarity in the
genus: as Glycyrrhiza 9 a sweet root, for the
Liquorice; Amaranthus, without decay, for
an everlasting flower; Helianthus, a sun-
flower; Litkospermum, a stony seed; Erio-
calia*, a flower with a singularly woolly base
or cup ; Origanum, an ornamental mountain
plant; Hemerocallis, a beauty of a day;

* When I named this genus in Exotic Botany, I was
not aware of its having previously been published by
M. Billardierc under the name of Actinotus ; a name
however not tenable in Botany, because it has long been
preoccupied in Mineralogy.

374 GENERIC NAMES IN

Arenaria, a plant that inhabits sanely places ;
and Gypsophila, one that loves a chalky soil.
Such as mark the botanical character of the
genus, when they can be obtained for a
nondescript plant, are peculiarly desirable :
as Ccratopetalum, from the branched horn-
like petals; Lasiopetalum, from the very sin*
gularly woolly corolla; Calceolaria, from the
shoe-like figure of the same part ; Concilium,
from the exact resemblance of its fruit to a
bivalve shell.

In ail ages it has been customary to dedi-
cate certain plants to the honour of distin-
guished persons. Thus Euphorbia comme-
morates the physician of Juba a Moorish
prince, and Geniiana immortalizes a king of
Illyria. The scientific botanists of modern
times have adopted the same mode of pre-
serving the memory of benefactors to their
science; and though the honour may have
been sometimes extended too far, that is no
argument for its total abrogation. Some un*
couth names thus unavoidably deform our
botanical books ; but this is often effaced by
the merits of their owners, and it is allow-
able to model them into grace as much as

HONOUR OF BOTANISTS. 3/5

possible. Thus the elegant Tournefort made
Gundelia from Gundelscheimer ; which in-
duced me to choose Goodenia for my much
honoured and valued friend Dr. Goodenough,
though it has, when too late, been suggested
that Goodenovia might have been preferable.
Some difficulty has arisen respecting French
botanists on account of the additional names
by which their grandeur, or at least their
vanity, was displayed during the existence
of the monarchy. Hence Pittonia was ap-
plied to the plant consecrated to Pitton de
Tournefort; but Linnaeus preferred the name
by which alone he was known out of his own
country or in learned language, and called
the same genus Tonrnefortia. Thus we have
a Fontainesia and a Louichea, after the ex-
cellent Louiche Desfontaines ; but the latter
proving a doubtful genus, or, if a good one,
being previously named Pteranthus, the
former is established. We have even in Eng-
land, by a strange oversight, both Stuartia
and Butea after the famous Earl of Bute ;
but the former being long ago settled by
Linnaeus, the latter, since given by Kcemg,
is totally inadmissible, on any pretence what-

376 GENERIC NAMES IN

ever, and the genus which bears it must have
a new appellation. In like manner my own
Humect, Exot, Boi. t. \> has been called in
France Calomeria after the present Emperor,
by the help of a pun, though there has long
been another genus Bonapartea, which last
can possibly be admitted only in honour of
the Empress, and not of her consort, who
has no botanical pretensions. Our own be-
loved sovereign could derive no glory from
the Georgia* of Ehrhart; but the St relit zia
of Aiton stands on the sure basis of botani-
cal knowledge and zeal, to which I can bear
ample and very disinterested testimony.

Linnoeus, in his entertaining book Critica
Botanica, p. 79? has in several instances
drawn a fanciful analogy between botanists
and their appropriate plants, thus —

Banhinia, after the two distinguished bro-
thers John and Caspar Bauhin, has a two-
lobed or twin leaf.

Scheuchzeria, a grassy alpine plant, com-
memorates the two Scheuchzers, one of whom
excelled in the knowledge of alpine produc-
tions, the other in that of grasses.

* Tetraphlsoi Hedwig and Engl. Bot. t. 1020.

HONOUR OF BOTANISTS. 377

Dorstenia, with its obsolete flowers, devoid
of all beauty, alludes to the antiquated and
uncouth book of Dorstenius.

Hernanciid) an American plant, the most
beautiful of all trees in its foliage, but fur-
nished with trifling blossoms, bears the name
of a botanist highly favoured by fortune, and
allowed an ample salary for the purpose of
investigating the natural history of the West-
ern world, but whose labours have not an-
swered the expense. On the contrary

Magnolia with its noble leaves and flowers,
and

Dillenia with its beautiful blossoms and
fruit, serve to immortalize two of the most
meritorious among botanists.

Linncea, " a depressed, abject, Lapland
plant, long overlooked, flowering at an early
age, was named by Gronovius after its pro-
totype Linnaeus."

In pursuance of the same idea Dicksonia,
a beautiful and curious fern, is well devoted
to our great cryptogamist ; Knappia, a small
and singular grass, to an author celebrated
for his minute and curious drawings of that
tribe; Sprengelia, to one distinguished for

378 " REMARKS ON

illustrating the impregnation of plants, which
the remarkable form and union of its anthers
serve to indicate ; while Smithia scnsitiva,
named by Mr. Dryander* in the Hortus
Kewensis of our mutual friend Aiton, could
at that time be merited only by an original
treatise on the Irritability of Plants -j-, to
which the specific name happily alludes.

The generic name being fixed, the specific
one is next to be considered. With respect-
to this, Rivinus has the merit of originality,
having been the first to contrive naming each
plant in two words. But his names were
meant for specific definitions, for which they
are totally inadequate. Linnaeus, in construct-
ing his more accurate and full specific cha-
racters, intended the latter should serve as
names, and therefore called them nomina
specified. When he, most fortunately for
the science and for the popularity of his whole
System of Nature, invented the present sim-
ple specific names, he called them nomina
trivialia, trivial, or for common use; but
that term is now superfluous.

* Salisb. Hort. 342. f fW. Trans- for 1788*

SPECIFIC NAMES. 379

Specific names should be formed on similar
principles to the generic onf s ; but some ex-
ceptions are allowed, not only without incon-
venience, but with great advantage. Such
as express the essential specific character are
unexceptionable, as Bauksia serrata, inte-
grifolia, dentata, &c; but perhaps those
which express something equally certain, but
no,t comprehended in that character, are still
more useful, as conveying additional informa-
tion, like Ixora alba and coccinea, Scleran-
thns annum and peremtis, Aletris fragrans,
Saxifraga cernua, &c; for which reason it is
often useful that vernacular names should
not be mere translations of the Latin ones.
Comparative appellations are very good, as
Banksia ePicifolia, Andromeda salicifoUa *,
Saxifraga bry aides. Milium cimicinum, Ely*-
tnus Hystrix, Pedicularis Sceptrum. Names
which express the local situations of different
species are excellent, such as Mtlampyrum

* Some botanists write ericcefolia, salicisfnlirt, Unguce-
formis^ he, instead of following the analogy of the La-
tin in forming adjectives with an i, as palmifcr from
palma, ce; laccifer, from bacca, ce ; larbiger, from
barla, ee ; &c.

3S0 REMARKS ON

arvense, pratense, nemorosum and sylvati-
cum, Car ex arenaria, uliginosa and sylvatica,
as well as aquatica, maritima, rupestris, al-
pina, nivalis, used for many plants. But
names derived from particular countries or
districts are liable to much exception, few
plants being sufficiently local to justify their
use. Thus Ligusticum cornubiense is found,
not only in Cornwall, but in Portugal, Italy
and Greece ; Schwenkia americana grows in
Guinea as well as in South America. Such
therefore, though suffered to remain on the
authority of Linnaeus, will seldom or never
be imitated by any judicious writer, unless
Troll ius europcEiis and asiaticus may justify
our naming the third species of that genus,
lately brought from America, americanus.
The use of a plant is often commodiously
expressed in its specific name, as Brassica
oleracea, Papaver somniferum, Inocarpus
edulis; so is likewise its time of flowering,
as Primula veris, Leucojum vernum 9 (tstivtim
and autumnale, and Helleborus hy emails.

When a plant has been erroneously made
into a new genus, the name so applied to it
may be retained for a specific appellation, as

specific names; 381

Lathrcea Phelypcea, and Bartsia Gymnandra;
which may also be practised when a plant has
been celebrated, either in botanical, medical,
or any other history, by a particular name,
as Origanum Dictamnus, Artemisia Dra-
cunculus, Lauras Cinnamomum, Selinwn
Carvifolia, Carica Papaya. In either case
the specific name stands as a substantive, re-
taining its own gender and termination, and
must begin with a capital letter; which last
circumstance should be observed if a species
be called after any botanist that has more
particularly illustrated it, as Cortusa Mat-
thioli and C. Gmelini, Duranta Plumierii,
and Mutisii. The latter genus suggests an
improvement in such kind of names. The
genitive case is rightly used for the person
who founded the genus, IX Plumierii; IX
Mutisiana might serve to commemorate the
finder of a species, while D. Ellisia implies
the plant which bears it to have been once
called Ellisia.

There is another sort of specific names in
the genitive case, which are to me absolutely
intolerable, though contrived by Linnaeus in
his latter days. These are of a comparative

^82

SPECIFIC NAMES.

kind, as Lobelia Coliimnea, meaning Co-
lumne<e for mis. We may allow a few such,
already established, to remain, but no ju-
dicious author will imitate them.

Botanists occasionally adapt a specific name
to some historical fact belonging to the plant
or to the person whose name it bears, as Lin-
ncea boreal is from the great botanist of the
Dorth ; Murrcca exotica after one of his fa-
vourite pupils, a foreigner ; Brotcallia de-
miss a and data, from a botanist of humble
origin and character, who afterwards became
$ lofty bishop, and in whose work upon wa-
ter I iind the following quotation from Se-
neca in the hand-writing of Linnaeus : " Many
might attain wisdom, if they did not sup-
pose they had already reached it." In like
manner Buffonia tenuifolia is well known to
be a satire on the slender botanical pretensions
of the great French zoologist, as the Hillia
parasitica of Jacquin, though perhaps not
meant, is an equally just one upon our pomp-
ous Sir John Hill I mean not to approve of
such satires. They stain the purity of our
lovely science. If a botanist does not de-
serve commemoration, let him sink peaceably

CHANGES OF NAMES. 383

into oblivion. It savours of malignity to
make his crown a crown of thorns, and if the
application be unjust, it is truly diabolical.

Before I conclude the subject of nomen-
clature, I beg leave to offer a few reflections
on changes of established names. It is ge-
nerally agreed among mankind that names of
countries, places, or things, sanctioned by
general use, should be sacred ; and the study
of natural history is, from the multitude of
objects with which it is conversant, neces-
sarily so encumbered with names, that stu-
dents require every possible assistance to fa-
cilitate the attainment of those names, and
have a just right to complain of every need-
less impediment. The grateful Hollanders
named the island of Mauritius after the hero
wbo had established their liberty and pro-
sperity; and it ill became the French, at that
period dead to such feelings, to change it,
when in their power, to Isle de France, by
which we have in some late botanical works
the barbarous Latin of Insula Francice. Nor
is it allowable to alter such names, even for
the better. Americo Vespucci had no very
great pretensions to give his own name to a
2

384 RIGHT OP OCCASIONALLY

quarter of the world, yet it is scarcely pro-
bable that Columbia will supersede America,
In our science the names established through-
out the works of Linnaeus are become cur-
rent coin, nor can they be altered without
great inconvenience. Perhaps, if he had
foreseen the future authority and popularity
of his writings, he might himself have im-
proved upon many which he adopted out of
deference to his predecessors, and it is in some
cases to be regretted that he has not suffi-
ciently done so. In like manner, the few great
leaders in natural knowledge must and will
be allowed to ward off and to correct, from
time to time, all that may deform or enfee-
ble the prevailing system. They must choose
between names nearly of the same date, and
even between good and bad ones of any date.
A botanist who, by the strength of his own
superior knowledge and authority, reforms
and elucidates a whole tribe of plants hitherto
in confusion, as a Hedwig in Mosses, or
Acharius in Lichens, ought to be unshackled
in every point in which he can be of service.
His wisdom will be evinced by extreme cau-
tion and reserve in using his liberty with re-

CHANGING NAMES. 385

spect to new names, but more especially new
terms; and, after all, lie will be amenable
to the general tribunal of botanists, and the
judgment of those who come after him. Few
indeed are illustrious enough to claim such
privileges as these. Those who alter names,
often for the worse, according to arbitrary
rules of their own, or in order to aim at con-
sequence which they cannot otherwise attain,
are* best treated with silent neglect. The
system should not be encumbered with such
names, even as synonyms.

When, however, solid discoveries and im-
provements are made in the science ; when
species or genera have been confounded by
Linnaeus himself, and new ones require to be
separated from them, the latter must neces-
sarily receive appropriate appellations; as
also when a totally wrong and absurd name
has by mistake been given, as Begonia ca-
pensis ; in such cases names must give place
to things, and alterations proceeding from
such causes must be submitted to. Thus I
believe Mr. Salisbury's Castalia is well sepa-
rated from Nympluea. See Annals of Bo-
tany 9 v. 2. 71*

2 c

386 COMPOUND

A great and just complaint has arisen in
my time among the cultivators of botany,
who found the names of many garden plants,
with which they had long been conversant,
altered for others without any apparent cause,
and in many instances for the worse ; as
Aristolochia macrophylla, an excellent and
expressive name, for a very unappropriate
one, A. Sipho. For this I am obliged to
censure my much regretted and very intelli-
gent friend L/Heritier. When he came to
England to reap the rich harvest of our un-
described plants, he paid no respect to the
generic or specific names by which Dr. So-
lander or others had called them, because
those names were not printed ; but he in-
dulged himself, and perhaps thought he con-
firmed his own importance, by contriving
new ones ; a factitious mode of gaining cele-
brity, to which his talents ought to have been
infinitely superior. Nor would it have been
easy to say how far this inconvenient plan
of innovation might have extended, had not
the Hortus Kewensis come forth to secure
our remaining property.

I have only to add a few words respecting

GENERIC NAMES. 367

a kind of generic names that has of late be-
come more common than Linnaeus probably
would have approved, though he has once or
twice allowed it; I allude to those com-
pounded either of two established names, or
of one combined with any other word. Of
the former number is Calamagrostis, formed
of Calamus and Agrostis, two Linnaean

names; and this is no where sanctioned by
i

any good authority. Happily the genus to
which it has negligently been applied is an
Arujido. Of the latter sort is Cissampelos,
formed of Cissus, another established genus,
and Ampelos, a Vine ; the latter not among
Linnaean names : also Eheagn as, constructed
Gf two old Greek names, neither of which is
now in botanical use by itself. These are
both expressly allowed by Linnaeus, nor in-*
deed can there be any objection to the latter.
Cissampclos may certainly justify Hyoscya-
muSy composed of Cyamus and a word de-
noting swine ; if not, this would prove an
objection to the reestablishment of Cyamus^
much more to the purpose than any that has
been advanced; for Hyoscyamus having been
so long and universally used in systematic;
o c o

^t V_- -.J

3S8 * COMPOUND NAMES.

botany, could scarcely give place, even to
its venerable prototype. On the same ground
only can several new generic names, used in
the fern tribe, be admitted. These are
formed out of Pteris, the established generic
appellation of a common Brake, with some
other Greek word prefixed ; as Angiopteris,
a Brake with a capsule, Tmesipteris, a cloven
Brake, and Can-opt eris a new Brake. What-
ever may become of the former two, I must
always protest against the last, given by the
celebrated Bergius to the Darea of Jussieu,
on account of its unexampled impropriety.
As well might any new genus, resembling a
Rose, be called Novarosa ; for though the
Greek language may assist us with regard to
sound, it can never make amends for a radi-
cal deficiencv of sense.

389

CHAPTER XXIII.

EXPLANATION OF THE LINN/EAN ARTI-
FICIAL SYSTEM.

JL he Linnaean System is, as I have already
observed, professedly artificial. Its sole aim
is to help any one to learn the name and his-
tory of an unknown plant in the most easy
and certain manner, by first determining its
Class and Order in this system ; after which
its Genus is to be made out by comparing
the parts of fructification with all the generic
characters of that Order ; and finally its Spe-
cies, by examining all the specific definitions
of the Genus. We thus ascertain the gene-
ric and specific name of our plant in Linmeus,
and under those we find an enumeration,
more or less ample, of its Synonyms, or the
different appellations it has received from
other writers, with a reference to figures in

390 OF TH£ LlNNiEAH

various books ; and as Linnaeus always cites
Bauhins Pinaa\ which is the common bo-
tanical catalogue, or index to all previous
works, we thus gain a clue to every thing
recorded concerning our plant. Of all this
mass of information and entertainment we
shall find nothing more concise, luminous, or
engaging, either with respect to the distinc-
tions, uses, or history of plants, than what is
diffused through the various publications of
Linnaeus himself; and the same may, with
at least equal truth, be said of those of his
works which illustrate the Animal kingdom.
His magic pen turns the wilds of Lapland
into fairy land. He has all the animals of
Sweden as much at his call, as our first pa-
rent while the terrestrial paradise was yet in
primaeval tranquillity. No writer whatever has
rendered the natural productions of the hap-
piest and most luxuriant climates of the globe
half so interesting or instructive as Linnaeus
has made those of his own northern country.
The Classes of the Linnsean System are
24, and their distinctions are founded on the
number, situation, or proportion of the Sta-
mens. The Orders are founded either on the

ARTIFICIAL SYSTEM. 391

number of the Pistils, or on some circumstance
equally easy, which we shall in due time ex-
plain.

The first eleven Classes are characterized
solely by the number of the Stamens, and
distinguished by names, of Greek derivation,
expressive of these distinctions.

1. Monandria. Stamen 1.

A small Class.

2. Diandria. Stamens 2.

3. Triandria 3.

4. Tetrandria 4.

5. Pentandria 5.

A numerous Class.

6. Hexandria 6.

7. Heptandria 7.

A very small Class*

8. octandria 8.

9. Enneandria — 9-

A small Class.

10. Decandria * 10.

11. Dodecandria 12 to 19.

12. Icosandria 20 or more

Stamens, inserted into the Calyx. Here
we first find the situation of the Stamens

392 LIXN^EAN

taken into consideration. They grow out
of the sides of the Calyx, often from a sort
of ring, as in the Strawberry. This is
truly a natural Class, as are several of the
following ones ; so that in these instances
the Linnsean method of arrangement per-
forms more than it promises. The charac-
ter of this Class is the more important,
as such a mode of insertion indicates the
pulpy fruits which accompany it to be infal-
libly wholesome, and this holds good, not
only when the stamens are numerous, but
in all other cases. Thus Ribes, the Cur-
rant and Gooseberry genus, whose 5 sta-
mens grow out of the calyx, stands in the
fifth class, a wholesome fruit, among many
poisonous berries. No traveller in the
most unknown wilderness need scruple to
eat any fruit whose stamens are thus situ-
ated ; while on the other hand he will do
well to be cautious of feeding on any
other parts of the plant,

13. Polyandria. Stamens numerous, com-
monly more so than in the last Class, and
inserted into the Receptacle, or base of

CLASSES. SQ'S

the flower, as in the Poppy, Anemone, &c.
The plants of this fine and numerous Class
are very distinct in nature, as well as cha-
racter, from those of the Icosandria.

14. Didystamia. Stamens 2 long and 2
short. Here proportio?i comes to our as-
sistance. This is a natural Class, and con-
tains most of the labiate, ringent or per-
sonate flowers, as the Dead-nettle, Snap-
dragon, Fox-glove, &c.

15. Tetradynamia. Stamens 4 long and
2 short. A very natural Class, compre-
hending all the Cruciform flowers, as the
Wall-flower, Stock, Radish, Mustard, &c.
Ckome only does not properly belong to
the rest.

16. Monadelphia. Stamens uniwteby
their filaments, more or less extensively,
into one tube, as the Mallow tribe, in
which such union is very remarkable, and
the Geranium family, in which it is less
evident.

17- Diadelphia. Stamens united into 2

1

304 L1NN/EAN

parcels, both sometimes cohering together
at the base. This Class consists of Papi-
lionaceous flowers, and is therefore natural,
except that some such genera having di-
stinct Stamens are excluded, and referred
to the tenth Class, in consideration of their
number solely; as some ringent flowers
with only 2 Stamens are necessarily placed,
not in the 14th Class, but the 2d.

18. Polyadelphia. Stamens united into
more than 2 parcels, as in St. JohnVwort.
A small Class, in some points related to
Icosandria.

19. Syngenksia. Stamens united by their
Anthers into a tube, rarely by their Fila-
ments also ; and tli3 flowers are Com-
pound. A very natural and extremely
numerous Class. Examples of it are the
Dandelion, Daisy, Sunflower, &c,

£0. Gynandria. Stamens united with, or
growing out of the Pistil ; either proceed-
in^ from the Germen, as in Aristolochia,
Engl Bot. t< 398, or from the Style, as in

CLASSES. 395

the Orchis family. The Passion-flower is
wrongly put by Linnaeus and others into
this Class, as its stamens merely grow out
of an elongated receptacle or column sup-
porting the Germen.

21. Monoecia. Stamens and Pistils in se-
parate flowers, but both growing on the
same plant, or, as the name expresses,
dwelling in one house, as the Oak, Hazle,
and Fir.

22. Dioecia. Stamens and Pistils not only
in separate flowers, but those flowers situ-
ated on two separate plants, as in the
Willow, Hop, Yew, &c.

These two last Classes are natural when
the barren flowers have, besides the dif-
ference in their essential organs, a different
structure from the fertile ones in other re-
spects ; but not so when they have the
same structure, because then both organs
are liable to meet in the same flower. In
some plants, as Rkodiola, Engl. Bot. t 508,
each flower has always the rudiments of
the other organ, though generally ineffi-
cient.

Sg6 LINN^EAN CLASSES

23. Polygamia. Stamens and Pistils se-
parate in some flowers, united in others,
either on the same plant, or on two or
three different ones.

This Class is natural only when the se-
veral flowers have a different structure, as
those of A triplex ; but in this genus the
Pistil of the united flower scarcely pro-
duces seed. If, with Linnaeus, we admit
into Polygamia every plant on which
some separated barren or fertile flowers
may be f3und among the united ones,
while all agree in general structure, the
Class will be overwhelmed, especially with
Indian trees. I have therefore proposed
that regard should be had to their general
structure, which removes all such incon-
venience, and renders the Class much more-
natural.

24. Cryptogamia.. Stamens and Pistils
either not well ascertained, or not to be
numbered with any certainty, insomuch
that the plants cannot be referred to any
of the foregoing classes. Of this Ferns, Li-
chens, Sea-weeds and Mushrooms are ex-
amples.

AND ORDERS. 397

Appendix. PALMiE, Palm-trees, a
magnificent tribe of plants, chiefly tropical,
whose flowers were too little known, when
Linnseus wrote, to serve the purposes of
classification ; but they are daily clearing
up, and the Palms are found generally
to belong to the Classes Monoecia, Dioecia,
or Hexandria.

The Orders of the Linneean System are,
in the first 13 Classes, founded on the num-
ber of the Styles, or on that of the Stigmas
when the Styles are wanting, which occurs in
Viburnum. Such Orders are accordingly
named

Monogynia. Style, or sessile Stigma, 1,

Digynia. Styles, or sessile Stigmas, 2.

Trigynia 3.

Tetragynia ■ 4.

Pentagynia 5.

Hexagynia ■ 6,

of very rare occurrence.

Heptagynia ■ 7>

still more unusual.

OcTAGYNIA ' 8>

scarcely occurs at all.

3Q& LINN-flEAN

Enneagynia. Styles, or sessile Stigmas, 9*
of which there is hardly an instance.

Decagynia -» 10.

Dodecagynia about 12.

Polygyria • ■ — many.

The 2 Orders of the 14th Class, Didynamia,
both natural, are characterized by the fruit,
as follows :

1. Gymnospermia. Seeds naked, almost
universally 4.

2. Angiospermxa. Seeds in a capsule,
numerous.

The 2 Orders of the 15th Class, Tetr ady-
namia, both very natural, are distinguished
by the form of the fruit, thus :

1. Si licu los a. Fruit a Silicida, Pouch*
or roundish Pod.

2. Siliquosa. Fruit a Siliqua, or long
Pod.

The Orders of the lfith, 17th and 18th
Classes, Monadelphia, Diadclphia and Poly a-
delphia, are founded on the number of the
Stamens, that is, on the characters of the first
13 Classes.

The Orders of the great natural 19th Class,
Syngenesia, are marked by the united or se-
parated, barren, fertile, or abortive, nature of
the florets.

1. Polygamia iEQUALis. Florets all per-
fect or united, that is, each furnished with
perfect Stamens, a Pistil, and one Seed.

%. Polygamia supeiiflua. Florets of
'the disk with Stamens and Pistil ; those of
the radius with Pistil only, but each, of
both kinds, forming perfect Seed.

3. Polygamia frustiia^ea. Florets of
the disk as in the last ; those of the radius
with merely an abortive Pistil, or with not
even the rudiments of any. This is a bad
Order, for reasons hereafter to be ex-
plained.

4. Polygamia necessaria. Florets of
the disk with Stamens only, those of the
radius with Pistils only.

5. Polygamia segreg ata. Several flow-
ers, either simple or compound, but with
united anthers, and with a proper calyx,
included in one common calyx.

400 LINNjEAN

Linnaeus has a 6th Order in this Class,
named Monogamia, consisting of simple
flowers with united anthers ; but this I have
presumed to disuse, because the union of
the anthers is not constant throughout the
species of each genus referred to it, witness
Lobelia and Viola, while on the contrary
several detached species in other Classes
have united anthers, as in Gentiana, EngL
Hot. t. 20. These reasons, which show
the connection of the anthers of a simple
flower to be neither important in nature,
nor constant as an artificial character, are
confirmed by the plants of this whole Lin-
nsean Order being natural allies of others
in the 5th Class, and totally discordant,
in every point, from the compound synge-
nesious flowers.

The Orders of the 20th, 21st and 22d
Classes are distinguished by the characters of
some of the Classes themselves which precede
them, that is, almost entirely by the number
of their Stamens ; for the union of the anthers
in some of them is, for the reasons just given,
of no moment.

ORDERS. 401

The Orders of the 23d Class, Poiygamia,
are, according to the beautiful uniformity of
plan which runs through this ingenious sy-
stem, distinguished upon the principles of the
Classes immediately preceding.

1. Moistoecia has flowers with Stamens and
Pistils on the same plant with others that
have only Pistils, or only Stamens ; or
perhaps all these three kinds of blossoms
occur; but whatever the different kinds
may be, they are confined to one plant.

2. Dioecia has the two or three kinds of
flowers on two separate plants;

3. Trioecia has them on three separate
plants, of which the Fig is the only real
example, and in that the structure of the
flowers is alike in all.

The Orders of the 24th Class, Cryptoga-
?nia, are professedly natural. They are 4 in
Linnaeus, but we now reckon 5.

1. Filices. Ferns, whose fructification is

obscure, and grows either on the back,

summit, or near the base of the leaf,

■thence denominated a frond. See p. 133.

2 D

402 LINN^EAN

2. Muse i. Mosses, which have real sepa-
rate leaves, and often a stem ; a hood-like
corolla, or calyptra, bearing the style, and
concealing the capsule, which at length
rises on a stalk with the calyptra, and
opens by a lid.

3. Hepatic.^. Liverworts, whose herb is
a frond, being leaf and stem united, and
whose capsules do not open with a lid.
Linnseus comprehends this Order under
the following.

4. ALGiE. Flags, whose herb is likewise a
frond, and whose seeds are imbedded,
either in its very substance, or in the disk
of some appropriate receptacle.

5. Fungi. Mushrooms, destitute of herbage,
bearing their fructification in a fleshy sub-
stance.

Such are the principles of the Linnaean
Classes and Orders, which have the advan-
tage of all other systems in facility, if not
conformity to the arrangement of nature ;
the latter merit they do not claim. They
are happily founded on two organs, not only
essential to a plant, but both necessarily pre*

ORDERS. 403

sent at the same time ; for though the Orders
of the 14th and 15th Classes are distinguished
by the fruit, they can be clearly ascertained
even in the earliest state of the germen*.

Tournefort founded his Orders on the fruit ;
and his countryman Adanson is charmed with
the propriety of this measure, because the
fruit comes after the flower, and thus prece-
dence is given to the nobler part which di-
stinguishes the primary divisions or Classes !
But happily the laws of a drawing-room do
not extend to philosophy, and we are allowed
to prefer parts which we are sure to meet
with at one and the same moment, without
waiting a month or two, after we have made

* An instance apparently to the contrary occurs in
the history of my Haslingia coccinea, Exot. Bot. t. SO,
a plant most evidently, both by character and natural
affinity, belonging to the Didynamia Gymnospermia, but
as I could no where find it described in that. Order, I
concluded it to be unpublished ; and was not a little sur-
prised to be told some time afterwards, that it was extant
in the works of my friends Retzius and Willdenow,
under Didynamia Angiospermia, by the name of Holms'-
kioldia, after a meritorious botanist. This last name
therefore, however unutterable, must remain; and I
wish the Linnsean system, as well as myself, might be
as free from blame in all other cases as in this,
2 d 2

404 DIFFICULTIES IN THE

out the Class of a plant, before we can settle
its Order.

The Linnsean System, however, like all hu-
man inventions, has its imperfections and dif-
ficulties. If we meet in gardens with double
or *monstrous flowers, whose essential organs
of fructification are deformed, multiplied, or
changed to petals ; or if we find a solitary
barren or fertile blossom only ; we must be
at a loss, and in such cases could only guess
at a new plant from its natural resemblance
to some known one. But the principal im-
perfection of the System in question consists,
not merely in what arises from variations in
number or structure among the parts of a
flower, against which no system could provide,
but in the differences which sometimes occur
between the number of Stamens, Styles, &c,
in different plants of the same natural genus.
Thus, some species of Cerastium have only 4,
others 5, Stamens, though the greater part
have 10. Lychnis clloica has the Stamens on
one plant, the Pistils on another, though the
rest of the genus has them united in the same
flower ; and there are several similar in-
stances ; for number in the parts of fructifica-

LINN^EAN SYSTEM. 405

lion is no more invariable than other charac-
ters, and even more uncertain than such as
are founded on insertion, or the connexion of
one part with another. Against these incon-
veniences the author of this System has pro-
vided an all-sufficient remedy. At the head
of every Class and Order, after the genera
which properly belong to them, he enume-
rates, in italics, all the anomalous species of
genera stationed in other places, that, by
their own peculiar number of Stamens or
Styles, should belong to the Class or Order
in question, but which are thus easily found
with their brethren by means of the index.

It is further to be observed that Linnaeus,
ever aware of the importance of keeping the
natural affinities of plants in view, has in each
of his artificial Orders, and sections of those
Orders, arranged the genera according to
those affinities ; while at the head of each
Class, in his Sy sterna VcgetabUium, he places
the same genera according to their technical
characters ; thus combining, as far as art can
keep pace with nature, the merits of a natural
and an artificial system. His editors have
seldom been aware of this ; and Murray

406 NATURAL SYSTEM

especially, in his 14th edition of the book
just mentioned, has inserted new plants with-
out any regard to this original plan of the
work.

From the foregoing remarks it is easy to
comprehend what is the real and highly im-
portant use of the Genera Plant arum of
Jussieu arranged in Natural Orders, the most
learned botanical work that has appeared
since the Species Plant arum of Linnaeus,
and the most useful to those who study the
philosophy of botanical arrangement. The
aim of this excellent author is to bring the
genera of plants together as much as possible
according to their natural affinities ; con-
structing his Classes and Orders rather from
an enlarged and general view of those affini-
ties, than from technical characters previ-
ously assumed for each Class or Order ; ex-
cept great and primary divisions, derived
chiefly from the Cotyledons, the Petals, and
the insertion of the Stamens. But his cha-
racters are so far from absolute, that at the
end of almost every Order we find a number
of genera merely related to it, and not pro-
perly belonging to it, and at the end of the

OF JUSSIEU, 407

system a very large assemblage of genera in-
capable of being referred to any Order what-
ever. Nor could a learner possibly use this
system as a dictionary, so as to find out any
unknown plant. The characters of the Or-
ders are necessarily, in proportion as those
Orders are natural, so widely and loosely
constructed, that a student has no where to
fix ; and in proportion as they are here and
there more defined, this, or any other system,
becomes artificial, and liable to the more ex-
ceptions. The way therefore to use this va-
luable work, so as to ascertain an unknown
plant, is, after turning to the Order or Genus
to which we conceive it most probably allied,
to read and study the characters and obser-
vations there brought together, as well as all
to which they may allude. We shall find we
learn more from the doubts and queries of
Jussieu than from the assertions of most other
writers. We shall readily perceive whether
our plant be known to him or not ; and if at
the same time we refer it, by its artificial
characters, to the Linnaean System, we can
hardly fail to ascertain, even under the most
difficult circumstances, whether it be de-

408 SYSTEM OF JUSSIEU.

scribed by either of these authors. A stu-
dent may acquire a competent knowledge of
natural orders, with very great pleasure to
himself, by repeatedly turning over the work
of Jussieu with any known plants in his
hand, and contemplating their essential ge-
neric characters in the first place, and then
what regards their habit and affinities ; pro-
ceeding afterwards to combine in his own
mind their several points of agreement, till he;
is competent to form an idea of those assem-
blages which constitute natural Classes and
Orders. This will gradually extend his ideas ;
whereas a contrary mode would only con-
tract them, and his Jussieu would prove,
merely an artificial guide, without the advan«
tages of facility or perspicuity.

409

CHAPTER XXIV.

ILLUSTRATIONS OF THE LlNNiEAN
CLASSES AND ORDERS.

I proceed to a compendious view of the
Linncean Classes and Orders, which will serve
to illustrate many things in the preceding
pages.

Class 1. Monandria. Stamen 1.
This contains only two Orders.
1. Monogynia. Style 1. Here we find the
beautiful exotic natural order called Sci-
taminece, consisting of Cardamoms, Gin-
ger, Turmerick, &c, hitherto a chaos, till
Mr. Roscoe, in a paper printed in the 8th
vol. of the Linnaan Society's Transactions,
reduced them to very natural and distinct
genera by the form of the filament. See
Eiot. Bot. t. 102, 103, 106—8.

410 MONANDRIA, DIANDRIA.

Salicornia, Engl. Bot. t. 415 and 1691,
and Hippuris, t. 763, are British examples
of Monandria Monogynia.

Valeriana (Class 3) has some species
with one stamen.

2. Digynia* Styles 2. Contains Corispermum,
Fl Grcee. t, 1, Blitum, Cart. Mag. t.2l6,
and a few plants besides.

Class 2. Diandria. Stamens 2.-— Orders 3,

1. Monogynia. This, the most natural and
numerous Order, comprehends the elegant
and fragrant Jasminece, the Jasmine, Lilac,
Olive, &c. — also Veronica, Engl. Bot. t. 2,
1027, 6 C 23, 783, &c— and a few labiate
flowers with naked seeds, as Salvia, Engl,
BGt. t. 153, 154, Rosemary, &c, natural
allies of the 14th class; but having only
two stamens, they are necessarily ranged
here in the artificial system.

2. Digynia consists only of Anthoxanthum,
a grass, Engl. Bot. t, 647, which for the
reason just given is separated from its na^
tural family in the third class.

3. Trigynia — has only Piper, the Pepper, a
large tropical genus.

TRIANDR1A. 411

Clasps 3. Triandria. Stamens 3.— Orders 3.

1. Monogynia. Valeriana, Engl Bot. t. 698,
1591 and 1531, is placed here because
most of its species have three stamens.
See Class 1. Here also we find the sword-
leaved plants, so amply illustrated in Cur-
tis's Magazine, Iris, Gladiolus, Liia, &c,
1 also Crocus, Engl Bot. t. 343, 344, 491,
and numerous grass-like plants, Schamus,
Cy penis, Scirpus, see Fl. Grcec. v. l,and
EmL Bot. U 950, 1309, 542, 873, &c,

3. Digynia. This important Order consista
of the true Grasses; see p. 127. Theitf
habit is more easily perceived than de-
fined ; their value, as furnishing herbage
for cattle, and grain for man, is suffi-
ciently obvious. No poisonous plant is
found among them, except the Lolium
temuhntum, Engl. Bot. t. ll c 24, said to
be intoxicating and pernicious in bread.
Their genera are not easily defined. Lin-
naeus, Jussieu, and most botanists pay re-
gard to the number of florets in each
spikelet, but in Arundo this is of no mo-

412 TRIANDRIA.

ment. Magnificent and valuable works
on this family have been published in Ger-
many by the celebrated Schreber and by
Dr. Host. The Fl. GrcEca also is rich in
this department, to which the late Dr. Sib-
thorp paid great attention. Much is to be
expected from scientific agriculturists; but
Nature so absolutely, in general, accom-
modates each grass to its own soil and sta-
tion, that nothing is more difficult than to
overcome their habits, insomuch that few
grasses can be generally cultivated at plea-
sure.

3. Trigynia is chiefly composed of little
pink-like plants, or Caryopliyllece, as Ho~
losteum, EngL Bot. t. 27.

Tilltea ??mscos.a, t. 11 6, has the number
proper to this order, but the rest of the
genus bears every part of the fructification
in fours. This in Linnaean language is ex-
pressed by saying the flower of Tilkca is
quadrifidus*, four-cleft, and T. muscosa
excludes, or lays aside, one fourth of the
fructification.

* See Linn. Sp. PL 186, and Curt. Lond.fasc. 6. t. 31.

TETRANDMA; 413

Class 4. Tetrandria. Stamens 4. — Orders 3.

1. Monogynia. A very numerous and vari-
ous Order, of which the Protectees make
a conspicuous part, consisting of Protect,
Bariksia, Lambertia, Embothrhim, &c.
See botany of New Holland, ^. 7— 10.
Scabiosa, Engl Bot. t. 659; Plant ago,
t. 1558, 1559, remarkable for its capsula
circumscissa, a membranous capsule, se-
parating by a complete circular fissure into
two parts, as in the next genus, Centim-
culus, t. 531 ; Rubia, t. 851, and others
of its natural order, of whose stipulation
we have spoken p. 219? are found here,
and the curious Epimedium, t. 438.

2. Digynia. Buffonia, t. 1313.

Cuscutu, placed here by Linnaeus, is
best removed to the next class.

3. Tetragyxia. Ilex, t. 496, a genus
sometimes furnished with a few barren
flowers, and therefore removed by Hudson
to the 23d class, of which it only serves
to show the disadvantage ; Potamogeton,
t. 168, 3/6, and Buppia, t. 136, are ex-

41 4 PENT AND III A,

amples of this Order. They all have sessile
stigmas.

Class 5. Pcntandria. Stamens 5. Avery
large class. — Orders 6*.

I. Monogynia. One of the largest and most
important Orders of the whole system.
The genera are enumerated first artificially,
according to the corolla being of one petal
or more, or wanting ; inferior or superior ;
with naked or covered seeds ; but stand
in the system according to their affinities,
and compose some natural orders ; as
Asperifolice, rough-leaved plants, which
have a monopetalous inferior corolla, and
four naked seeds, with always more or less
of spinous bristles or callous asperities on
their foliage ; see Borago, Engl. Bot. t. 36,
Lycopsis, t. 938, and Edition, t. 181.
Next comes that most elegant tribe of
spring plants denominated Precice by Lin-
naeus, Primula, t.A — 6, Cyclamen, t. 548,
the charming alpine Arefia, and Androsace,
Curt. Mag. t. 7 43. These are followed
by another Linnaean order, nearly akin,
called Rotacea, from the wheel-shaped
corolla, Hottonia, Engl. Bot. t. 364, Lysi-

!>ENTANDRIA. 415

tnachidy t. 761. — Convolvulus and Cam-
panula, two large well-known genera, come
afterwards ; then Lobelia, t. 140, Impa-
Hens, t. 937, and Viola, t. 619, 620> brought
hither from the abolished Linnaean order
Si/ngenesia Monogamia. The Luridce fol-
low, so called from their frequently dark,
gloomy aspect, indicative of their narcotic
and very dangerous qualities ; as Datura,
t. 1288, Hyoscyamus, t. 591, Atropa,
1* 592, and Nicotiana, or Tobacco. In a
subsequent part we meet with the Vine,
Currant and Ivy, and the Order finishes
with some of the natural family of Con-
torted, so called from their oblique or
twisted corolla, and which are many of
them very fine plants, as Vinca, t. 514,
917. They often abound with milky juice,
generally highly acrid ; but Dr. Afzelius
met with a shrub of this order at Sierra
Leone, the milk of whose fruit was so
sweet, as well as copious, as to be used
instead of cream for tea. This is certainly
what no one could have guessed from ana-
'°Sy # Gardenia is erroneously reckoned
a contort a by Linnaeus.

4lb PENTANURIA,

2. Digynia begins with the remainder of
the Contort <z ; then follow some incomplete
flowers, as Chenopodium, t. 1033, Beta,
t. 285, and afterwards the fine alpine ge-
nus of Gentiana, t. 20, 493, 896, famous
for its extreme bitterness and consequent
stomachic virtues.

The rest of the Order consists of the very
natural Umbelliferous family, characterized
by having five superior petals, and a pair
of naked seeds, suspended vertically when
ripe from the summit of a slender hair-like
receptacle. Of the inflorescence of this
tribe, and the difficulties attending their
generic distinctions, we have spoken p* 309-
In Eryngium, t. 718 and 57, the umbel
is condensed into a capitulum, or conical
scaly head , showing an approach towards
the compound flowers, and accompanied,
as Jussieu observes, by the habit of a
Thistle. Lagoecia is justly referred to
this natural order by the same writer,
though it has only a solitary seed and style.
The Umbelliferce are mostly herbaceous ;
the qualities of such as grow on dry ground
are aromatic, while the aquatic species are

PENTANDRIA. 417

among the most deadly of poisons ; accord-
ing to the remark of Linnaeus, who detected
the cause of a dreadful disorder among
horned cattle in Lapland, in their eating
young leaves of Cicuta virosa, Engl. Boi.
i\ 479, under water.

Botanists in general shrink from the study
of the Umb'ellifefa, nor have these plants
much beauty in the eyes of amateurs ; but
they wi|l repay the trouble of a careful ob-
servation. The late M. Cusson of Mont-
pellier bestowed more pains upon them than
any other botanist has ever done ; but the
world has, as yet, been favoured with only
a part of his remarks. His labours met
with a most ungrateful check, in the un-
kindness, and still more mortifying stu-
pidity, of his wife, who, on his absence from
home, is recorded to have destroyed his
whole herbarium, scraping off* the dried
specimens, for the sake of the paper on
which they were pasted !
3. Trigyma is illustrated by the Elder, the
Sumach or Rhus, Viburnum, &c, also
Corrigiola, Engl. Hot. t. 668, and Tu-
niarlx, i, 1318, of which last one specie^,
germa?iica > has 10 stamens.

9 f

418 HEXANDRIA.

4. Tetragynia has only Evolvuhis, nearly
allied to Convolvulus, and the elegant and
curious Parnassia, t. 82.

5. Pentagynia contains St at ice 9 t.225, 102,
and 328, a beautiful maritime genus, with
a kind of everlasting calyx. The Flora
Grceca has many fine species. Linum or
Flax follows; also the curious exotic Aldro-
vanda, Dicks. Dr. PL 30; Drosera, Engl.
Pot. t. 867 — 9 ; the numerous succulent
genus Crassula ; and the alpine Sibbuldia,
t.<SS7, of the. natural order of Rosacece.

6. Polygynia. Myosurus, t. 435, a remark-
able instance of few stamens (though they
often exceed five) to a multitude of pistils.

Class 6. Hexandrla. Stamens 6. Orders 6.

1. Monogynia. This, as usual, is the most
numerous. The Liliaceous family, with
or without a spatha, called by Linnaeus
the nobles of the vegetable kingdom, con-
stitute its most splendid ornament. The
beautiful White Lily is commonly chosen
by popular writers to exemplify the sta-
mens and pistils. The less ostentatious ge-
nus of J uncus or Rush; which soon follows.

HEXANDRIA, 41 9

is more nearly allied to the Lilies than a
young botanist would suppose. Near it
^tand several genera which have little af-
finity to each other, and of these Capura
is a mistake, having been made out of a
specimen of Daphne indica, which chanced
to have but six stamens.

2.. Digynia has but few genera. The va-
luable Qryza, Rice, of which there now
seems to be more than one species, is the
most remarkable. It' is a grass with six
stamens.

3. Tfigyriia. See Rumex, Engl. Bot. t. 1533,
127 5 &c., some species of which has se-
parated flowers ; Tofieldia^ t. 536 ; and
Cofchicum, t. 133 and 1432.

4. Tetragynia. Petiveria alliacea, a plant
the number of whose stamens is not very
constant, and whose specific name is sup-
posed to allude, not only to its garlic scent,
but also to the caustic humour of the bo-
tanist whom it commemorates.

5. Ilexagynia. An order in Schreber and
Willdenow, contains Wcndlandia populi-

2 £2

420 HEPTANDRIA.

folia of the latter ; with Damasonium of
the former, a genus consisting of the Lin-
naean Stratiotes alismoi-des, Exot. Bot.
t. 15.
6. Polygynia. Alisma only— Engl. Bot.
t. 837, 775, &c.

Class 7- Heptandria. Stamens 7- Orders 4.

1. Monogynia* Trientalis, Engl. Bot. 1. 15,
a favourite plant of Linnaeus ; and JEscu-
luS) the Horse Chesnut. Several genera
are removed to this order by late writers.

2. Digynia. Limeum, an African genus,
only.

3. Tetragijiiia. Saururtis^ a Virginian plant.

Aponogeton, placed here by Linnaeus, is
now properly removed to Dodecandria. It
is an East Indian and Cape aquatic genus,
bearing above the water white fragrant
flowers in a peculiar spike, which is either
solitary or double.

4. Heptagynia. Sepias^ a Cape plant, very
nearly akin to Crassula, to which Thunberg
refers it. If its character in Linnaeus be
constant with respect to number, it is very

OCTANDRIA. 421

remarkable, having the calyx in 7 deep
segments, 7 petals, 7 germens, and con-
sequently 7 capsules.

Class 3. Octandria. Stamens 8. Orders 4.

l r Mpnogynia, A very various and rich or-
der, consisting of the well-known Tropceo-
lum or Nasturtium, whose original Latin
.name, given from the flavour of the plant,
like Garden Cresses, is now become its
English one in every body's mouth. The
elegant and fanciful Lihnaean appellation,
equivalent to a trophy plant, alludes to its
use for decorating bowers, and the re-
semblance of its peltate leaves to shields,
as well as of its flowers to golden helmets,
pierced through and through, and stained
with blood. See Linn. Hart. Cliff. 143.—
Epilobium, Engl Hot. t, 838, 795, &c,
with its allies, makes a beautiful part of this
order; but above all are conspicuous the
favourite Fuchsia, the chiefly American
genus Vaccinium, t. 4o6, 319, &c. ; the
immense and most elegant genus Erica,
so abundant in southern Africa, but not
known in America; and the fragrant

422 ENNEANDRIA.

Daphne, t. 1381, of which last the Levant
possesses many charming species. Acer.,
the Maple, is removed hither in FL Brit.
from the 23d class.

2. Digynia has a few plants, but little
known; among them are Galenia africana>
and Moehringia muscosa.

3. Trigynia. Polygonum, t. 436, 509, 941,
is a genus whose species differ in the num-
ber of their stamens and styles, and yet
none can be more natural. Here there-
fore the Linnaean system claims our indul-
gence. Paullinia and Cardiospermum are
more constant.

4. Tetragynia. Here we find the curious
Paris, t. 7, and A dost a, t. 453. Of the
former I have lately received a new species,
gathered by my liberal friend Buchanan
among the mountains of Nepal.

Class 9- Enneandria. Stamens 9- Orders 3.

1. Monogynia. Of this the precious genus
Laurifs, including the Cinnamon, Bay,
Sassafras, Camphor, and many other noble
plants, is an example.

DECANDRIA. 423

2. Trigynia has only Rheum, the Rhubarb,
nearly related to Rumex.

3. Hexagynia. Butomus umbellatus, Engl
Rot. t. 651, a great ornament to our rivers
and pools.

Class 10. Decandria. Stamens 10.
Orders 5.

1. Monogynia. A numerous and fine as-
semblage, beginning with a tribe of flowers
more or less correctly papilionaceous and
leguminous, which differ very materially
from the rest of that natural order in hav-
ing ten stout, firm, separate stamens. See
Cassia, Curt. Mag. L 107, 633, and
Sophora, t. 167 ; also Exot. Rot. t. 25—
27, and Annals of Rot any, v. 1. 501.

The Rata, Rue, and its allies, now be-
come very numerous, follow. See Tracts
on Nat. Hist. 287- Dictamnus, vulgarly
called Fraxinella, is one of them. Dionaa
muscipula, see p. 174, stands in this arti-
ficial order, as do the beautiful Kalmia,
Rhododendron, Andromeda, Arbutus and
Vyrola, Engl. Rot t. 213, &c.

424 DECANDR1A.

2. Digynia. Saxifraga, remarkable fcrvhar-t

ing the germen inferior, half inferior, and
superior, in different specie.-., a very rare
example, See Engl Bot. t. 1&7, 440,
663, 1009, 500, 501. Dianthus, the
Pink or Carnation tribe, and some of its
very distinct natural order, CaryophyllecE,
conclude the Decanchia Digynia.

3. Trigynia. The Cary op hylic ce are here
continued, as Cucubalus, t. 1577, Silene,
t. 465, 1398, Arenaria, t. 189, 512, very
prolific and intricate genera in the Levant.
Malpighia and Banisteria, beautiful plants
of the Maple family, which next occur,
have no affinity to the foregoing.

4. Pentagynia. Abounds in more Caryo-
phyllece, as Lychnis, t. 5/3, and Cerastium,
i- 789, 790. Cotyledon, t. 325, Sedum,
t. 1319, and Qtfalu, t. 7&1, are placed
here. Some of the last genus have the
filaments united at their base, and there-
fore should belong to the lGth class, — an-
other defect in the artificial system.

5. Decagynia. Consists of only Neurada,
with Phytolacca; the latter an irregular

DODECANDRIA. 425

genus as to stamens and styles, which
therefore afford good marks to discriminate
the species.

Class 11. Dodecandria. Stamens 12 to 19.
Orders 6.

1 » M-Qnogynia. A rather numerous and very
various order, with scarcely any natural af-
finity between the genera. Some of them
have twelve, others fifteen or more stamens,
which should be mentioned in their cha-
racters. Asarum, Engl. Bot. t. 1083, and
the handsome I.ythrum Salicarid, t. 1061,
also the American Snow-drop-tree, Halesia,
not rare in our gardens, may serve as ex-
amples of this order. Sterculia is very
properly removed hither from Gynandria
by Schreber and Willdenow, as its sta-
mens are not inserted above the germen.

2. Digynia consists of Heliocarpus, a very
rare American tree with a singularly fringed
or radiated fruit ; and Agrimonia, Engl.
Bot. t. 1335. The latter might as well
have been placed in the next class, with
which it agrees in natural order.

4 £6 1COSANDRLA.

3. Trigynia is chiefly occupied by Reseda,
the Mignonette, £.320,321, and Euphor-
bia, t. 256, 883, &c, one of the most
well defined and natural genera, of which
the punicea, Ic. Fict. t. 3, is a splendid
exotic species.

4. Tetragynia, in Schreber and Willdenow,
consists of CaUigorium, a genus illustrated
by L'Heritier in the Transactions of Linn.
Society, v, 1 ; and Aponogeton, already
mentioned p. 420.

5. Pentagynia has G linns, an insignificant
genus ; and Blackicelha, a doubtful one.

6. Dodecagynia is exemplified in Semper-
vivum, the Houseleek, Engl. Bot. t. 1320,
whose styles vary from 12 to 18 or 20.
Sempervivum sediforme, Jacq. Hort. Vind.
t. 81, is a Sedum with a superabundance
of parts in the fructification. Linnseus
confounded it with S. i^upestre.

Class 12. Icosandria. Stamens 20 or more,
inserted into the Calyx. Orders 3.

1. Monogynia consists of fine trees, bearing
for the most part stone fruits, as the Peach,

ICOSANDRIA. 427

Plum, Cherry, &c, though the leaves and
other parts are bitter, acrid, and, as we
have already mentioned, sometimes very
dangerous, owing to a peculiar essential
oil, known by its bitter-almond flavour.
See specimens of this family in Engl. Bot.
t. 1383, 706, 841, 842. The Myrtle tribe
is another natural order, comprehended
.chiefly under Icosandria Monogynies a-
bounding in a fragrant and wholesome
aromatic oil. These are plentiful in New
Holland. See Tr. of Linn. Soc* y. 3. 255,
also Exot. Bot. t. 42, 59, and 04. Caryo-.
phyllus aromaticus, the Clove, should on
every account be removed hither.

2. Pentagynia. In this order it is most con-
venient to include such plants as have
from two to five styles, and occasionally,
from accidental luxuriance only, one or
two more. An example of it is the very
natural family of the Pomace.ee, as Pyrus*
the Apple, Pear, Sec. Engl. Bot. t. 179,
350, 337 ; and Mespihis, t. 1523, Exot.
Bot. t. 18, 85. In this family some spe-
cies of the same genus have five, others
{hree, two, or only one style, and a corre-

428 ICOSANDRIA.

spending number of seeds. Spinea, nearly
allied to it, stands here, most of its species
having five styles, though some have a
much greater number ; see Engl. Hot.
i. 284, 960. Mesembryanthemum 9 a vast
and brilliant exotic genus, of a succulent
habit, abounding in alkaline salt, and a
few genera naturally allied to it, make up
the rest of the order.

3. Polygt/tiia. An entirely natural order of
genuine Rosaceous flowers, except possibly
Cahjcanthus. Here we find Rosa, Engl.
Bof. t. 1S7, 990—2; Rubus, LS26 9 827,
716; Fragaria, t 1.524; Potentilla, t. 88,
89,862; Torment ilia, t. 863,864; Geum,
t. 106; Dri/as, t. 451; and Comarum. A
t. I? 2 : all elegant plants, agreeing in the
astringent qualities of their roots, bark and
foliage, and in their generally eatable,
always innocent, fruit. The vegetable
kingdom does not afford a more satisfac-
tory example of a natural order, composed
of natural genera, than this ; and Linnaeus
has well illustrated it in the Flora Lap-
ponica. His genus Torment ilia, differing
from Pofentilla in number of petals and

POLYANDKIA. 429

segments of the calyx, though retained by
Jussieu, may perhaps be scarcely distinct;
yet there is a difference in their habit,
which has induced me to leave it for
farther consideration. Kaller united them
both with Fragaria and Comanun, which
the character and habit of the latter totally
forbid, and Gurrtner has well suggested a
«mark from the smoothness of the seeds in
Fragaria, (as well as Comarum.) to
strengthen that of its pulpy receptacle.
Whatever difficulties may attend these ge-
nera, how admirably does the fruit serve
us in Rosa, Rubus, Dryas and Geum, to
discriminate those whose leaves, flowers,
and habit all stamp them as distinct! A
student cannot do better than to study
this order and these genera, as an intro-
duction to the knowledge of more obscure
ones; and the beautiful plants which com-
pose it, mostly familiar to every body, are
easily obtained.

Class 13. Polyandria. Stamens numerous,
inserted into the Receptacle.

1. Monogynia, The genera of this order are

430 POLYASDRIA.

artificially distributed according to the
number of their petals, but not so arranged
in the body of the system. They form a
numerous and various assemblage of hand-
some plants, but many are of a suspected
quality. Among them are the Poppy, the
Caper-shrub, the Sangidnaria canadensis,
Curt. Mag. t. 162, remarkable for its
orange juice, like our Celandine, Engl.
Bot. t. 1581 ; also the beautiful genus
Cistus with its copious but short-lived
flowers, some of which (Engl. Bot. 1. 1321)
have irritable stamens ; the splendid aqua-
tic tribe of Nymphcea, &c, t. 159? 160.
But the precious Nutmeg and the Tea
are perhaps erroneously placed here by
Linnaeus, as well as the Clove ; while on
the other hand Cleome more properly be-
longs to this part of the system than to the
15th Class.

2. Digynia has principally the Paojiia,
t. 1513, variable in number of pistils, and
Fothergitta ahiifolia, an American shrub.

3. Trigynia. Delphinium the Larkspur, and
Aconitam the Monk's hood, two variable

POLYANDRIA. 431

and uncertain genera as to number of
pistils.

4. Tetragynia. Tefracera ought, by its
name, to have constantly four pistils, but
the rest of this order are very doubtful.
Caryocar* whose large rugged woody nuts
contain the most exquisite kernel ever
brought to our tables, and which is the
'same plant with Gartner's and Schreber's

Rhizobolus, as the excellent Willdenow
rightly judged, is not certain in number ;
and still less the Cimicifuga; whilst
Wahlbomia is probably a Tetracera : see
Willdenow.

5. Pentagynia contains chiefly Aquilcgia
the Columbine, and Nigella — both strictly
allied to genera in the third order. Reau-
muria indeed is here well placed. Some
Nigel Ice have ten styles.

6. Hexagynia consists of Stratiotes, Engl.
Hot. t. 379 ; and Brasenia, a new genus of
Schreber's with which I am not acquainted.

I would recommend an union of the
last five orders, for the same reason that

432 POLYANEiRiA,

influenced me in the preceding class. They
now only serve to keep natural genera
asunder, the species of which not only
differ among themselves as to number of
pistils, but each species is often variable
besides. The genera are so few that no
inconvenience could arise on that account.
I conceive such reforms, founded in expe-
rience not in theory, serve to strengthen
the system, by greatly facilitating its ap-
plication to practice.

Polygyria. An order for the most part
natural, comprehending some fine exotic
trees, as Dillenia, Exot. Bot. t. 2, 3, 92
and 93; Liriodendron, the Tulip-tree; the
noble Magnolia, &c»; a tribe concerning
whose genera our periodical writers are
falling into great mistakes. To these suc-
ceed a family of plants, either herbaceous
or climbing, of great elegance, but of acrid
and dangerous qualities, as Anemone, in a
single state the most lovely, in a double
one the most splendid, ornament of our
parterres in the spring; Airagene and
Clematis, so graceful for bowers: Thalic-

DIDYNAMIA. 433

tram, Adonis, Ranunculus, Trolfim 9 HeU
leborus and Caltha, all conspicuous in our
gardens or meadows, which, with a few
less familiar, close this class.

Nothing can be more injudicious than
uniting these two last classes, as some in-
experienced authors have done. They are
immutably distinct in nature and charac-
ters, whether we call the part which imme-
diately bears the stamens in the Icosandria
a calyx, with most botanists, or a recep-
tacle, with Mr. Salisbury in the 3th vol.
of the Linnsean Society's Transactions,
where, among many things which I wish
had been omitted, are some good remarks
concerning the distinction between calyx
and corolla. This the writer in question
considers as decided in doubtful cases by
the latter sometimes bearing the stamens,
which the former, in his opinion, never
really does.

Class 14. Didynamia. Stamens 2 long and
2 short. Orders 2, each on the whole
very natural.

1. Gymnospermia. Seeds naked, in the bot-

2 F

434 DIDYNAMIA.

torn of the calyx, 4, except in Fhryina,
which has a solitary seed. — Corolla mono-
petalous and irregular, a little inflated at
the base, and holding honey, -without any
particular nectary. Stamens in 2 pairs,
incurved, with the style between them, so
that the impregnation rarely fails. The
plants of this order are mostly aromatic,
and none, I believe, poisonous. The calyx
is either in 5 nearly equal segments, or 2-
lipped. Most of the genera afford excel-
lent essential characters, taken frequently
from the corolla, or from some other part.
Thus, Perilla has 2 styles, of which it is
an unique example in this class.

Mentha a corolla whose segments are
nearly equal, and spreading stamens. Ejigl.
Bot. t. 446—8.

Lavandula the Lavender, and Wes~
tringia, Tracts on Natural History, 277?
t. 3, have a corolla resupinata, reversed
or laid on its back.

Teucrium a deeply divided upper lip,
allowing the stamens and style to project
between its lobes. Engl. Bot t. 680.

Ajuga scarcely any upper lip at all,
• t. 77 and 489-

DIDYXAMIA. 435

Lamium has the mouth toothed on each
side, f% 76'8,

Prunella, t. 96 1, has forked filaments;
Cleonia 4 stigmas ; Prasium a pulpy coat
to its seeds. These instances will suffice
as clear examples of natural genera, di-
stinguished by an essential technical cha-
racter, in a most natural order.

2. AngibspeVmia. Seeds in a capsule, and
generally very numerous. — The plants of
this order have the greatest possible affinity
with some families in Pentandria Mbhogy-
nia. Some species even vary from one
class to the other, as Bigmmia radicans,
Curl. Mag. i. 48.5, and Antirrhinum
Linaria, Engh BoL t. 658, 26*0, in which
the irregular corolla becomes regular, and
the 4 unequal stamens are changed to 5
equal ones; nor does this depend, as has
been asserted, on the action of anv extrane-
ous ;m>; : n upon the stigmas of the parent
plant, neither are the seeds always abortive.
No method of arrangement, natural or ar-
tificial, could provide against such ano-
malies as these, and therefore imperfections
must be expected in every system.

436 TETRADYNAMIA.

Class 15. Tetradynamia. Stamens 4 long
and 2 short. Orders 2, perfectly natural.
Flowers cruciform.

1. Siliculosa. Fruit a roundish pod, or pouch.
In some genera it is entire, as Draba,
E?igL Bot. t. 586, and the Honesty or
Satin flower Lunaria : in others notched,
as Thlaspi, t. 1659, and Iberis, t. 52;
which last genus is unique in its natural
order in having unequal petals. Crambe,
t.9%&; Isatisy t.97', and Bunias, t.231;
certainly belong to this Order, though
placed by Linnaeus in the next.

2. Siliquosa. Fruit a very long pod. Some
genera have a calyx clausus, its leaves
slightly cohering by their sides, as Rapha-
nus, t. 856 ; Ckeiranthus, t. 462 ; Hes-
peris, t. 731 ; Brassica, t. 637 > &c.
Others have a spreading or gaping calyx,
asCWrfamme, 1. 1000; Sisymbrium, t. 855 ;
and especially Sinapis, t. 969 and t. 1677-

Cleome is a very irregular genus, allied
in habit, and even in the number of sta-
mens of several species, to the Bolyandria
Monogynia. Its fruit, moreover, is a cap-
sule of one cell, not the real two-celled

MONADELPHIA. 437

pod of this Order. Most of its species are
foetid and very poisonous, whereas scarcely
any plants properly belonging to this Class
are remarkably noxious, for I have great
doubts concerning the disease called Uer-
phania, attributed by Linnaeus to the seeds
of Raphanus Raphanistrum.

The Cruciform plants are vulgarly called
antiscorbutic, and supposed to be of an
alkalescent nature. Their essential oil,
which is generally obtainable in very small
quantities by distillation, smells like vola-
tile alkali, and is of a very acrid quality.
Hence the foetid scent of water in which
cabbages, or other plants of this tribe,
have been boiled.

Class 16. Monadelphia. Stamens united
by their filaments into one tube. Orders 8,
distinguished by the number of their sta-
mens.

I. Triandria is exemplified by Sisyrinchium,
Ic. Pict. t. 9, and Ferraria, Curt. Mag.
t. 144, 532, both erroneously placed by
Linnaeus in Gynandria. Also the singular
Cape plant Aphyteia, consisting of a large

438 MOSADELPHIA.

flower and succulent fruit, springing im-
mediately from the root, without stem or
leaves. On this plant Linnaeus published
a dissertation in 1775. Tamarindm has
lately been removed hither from the third
Class, perhaps justly.

2. Pentandria. Erodium, Engl. Boi. t. 902,
separated, with great propriety, from Ge-
ranium by L'Heritier; Hermdnnm, a
pretty Cape genus, Curt. Mag. t. 307 ;
and a few other plants, more or less akin
to the Mallow tribe, compose this Order ;
to which also strictly belong some species
of Lihum, Geranium, Sec. Passijlora,
removed from Gynandria^ belongs most
unquestionably to Pentandria Trigynia,
and by no means to this Class.

3. Ileptandria consists onbr of Pelargonium

of L/Heritier, an excellent genus, compri-
sing most of the Cape Geraniums, and
marked by its irregular flower, 7 stamens,
and tubular nectary.

4. Octandria contains Ailonia, Curt. Mag.
t. 173, named in honour of the excellent
and universally respected author of the

MONADEXPHIA. 43&

Hortus KewensLs. Phtia is, I believe justly,
placed here by Schreber and Willdenow.

5. Decandria. Geranium^ properly so caffed,
Engl Bot. t. 404, 405, 272, &c, is the
principal genus here. The late Professor
Cavanilles, however, in his Dissertationes
Bofanictf, referred to this Order a vast
number of genera, never before suspected
to belong to it, asBdnnisterih, Malpig&ia,
Turrcca, Melia, &c, on account of scfene
fancied union of their filaments, perhaps
through the medium of a tubular nectary ;
which principle is absolutely inadmissible ;
for we might just as well refer to Mona-
delphia every plant whose filaments are
connected by insertion into a tubular co-
rolla. Some species of Oxalic see p. 424,
belong to this Order ; as do several pa-
pilionaceous genera, of which we shall
speak under the next Class.

6. Endecandfia contains only the splendfd

South-American genus Bvppynect, trie num-
ber of whose stamens is different in differ-
ent species.

7- Dodccandriu, Stamens mostly 15, is cdm-

440 DIADELPHIX.

posed of some fine plants allied to the
Mallows, as Ptcrospermum, t. 620, Pen-
tapetes, &c.

& Polyandria, a very numerous and mag-
nificent Order, comprises, among other
things, the true Columniferce or Malvacece,
as Malva, Engl Bot. t. 67l, 754, Althcea,
t. 147, Hibiscus, SpiciL Bot. t. 8, Gossy-
phim the Cotton-tree, Alcea the Holly-
hock, &c. Stately and beautiful plants of
this Order, though not Malvacece, are
Carolinea, whose angular seeds are sold in
our shops by the name of Brasil nuts ;
Gustavia, named after the late King of
Sweden, a great patron of botany and of
Linnaeus ; Camellia, Curt. Mag. t. 42>
whose splendid varieties have of late be-
come favourites with collectors ; Stuariia,
Exot. Bot. t. 110; and Barringtonia, the
original Commersonia, Sonmrat Voy, a la
Nouv. Guinee, t. 8, 3.

Class'17. Diadelphia. Stamens united by
their filaments into 2 parcels, both some-
times cohering at the base, Orders 4,
distinguished by the number of their Sta-

DIADELPHIA. 441

mens. — Rowers almost universally papi-
lionaceous.

1. Pentandria. The only genus in this Or-
der is Momrieria, Lamarck, t. 59ft a ran*
little South American plant, whose natural
order is uncertain. It has a r'mgent co-
rolla, ternate leaves, a simple bristly pu-

' bescence, and is besprinkled with resinous
dots.

2. Hexandria. Saraca, in this Order, is as
little known as the Monnieria, except that
it undoubtedly belongs to the leguminous
family. It seems most allied to Brownea f
Jonesia, Afzelia, &c. Fimiaria, the only
genus besides, is remarkable for the great
variety of forms in its seed-vessel, whence
botanists who make genera from technical
characters, without regard to natural prin-
ciples, have injudiciously subdivided it.
See Engl Boi. u 588— 590, 943, 1471.

3. Qctandria. Polygala, f. 7ft is the prih*

cipal genus here. America and the Cape
of Good Hope abound in beautiful species
of it, and New Holland affords some new
genera, long confounded with this. Dal-

44S DIADELPHIA.

bergia is perhaps as well placed in the next
Order.

4. Decandria is by far the most numerous,
as well as natural, Order of this Class,
consequently the genera are difficult to
characterize. They compose the family of
proper Tapilionacea or Leguminoscc, the
Pea, Vetch, Broom, &c. Their stamens
are most usually 9 in one set, with a single
one separate.

The jzenera are arranged in sections va-
p °

riously characterized.

* Stamens' all united, that is, all in one
set. The plants of this section are really not
diadelphous but monadelphous. See Spartium,
Engl. Bot. t. 1339. Some of them, as Lu-
pinus, and Ulex, i. 742, 743, have indeed
the tenth stamen evidently distinguished from
the rest, though incorporated with them by
its lower part. Others have a longitudinal
slit in the upper side of the tube, or the lat-
ter easily separates there, as Ononis, t. 682,
without any indication of a separate stamen.
Here therefore the Linnaean System swerves
from its strict artificial laws, in compliance

DIADELPHIA. 443

with tlie decisive natural character which
marks the plants in question... We easily per-
ceive that character, and have only to ascer-
tain whether any papilionaceous plant we may
have to examine has 10 stamens, all alike se-
parate and distinct, in which case it belongs
to the 10th Class, or whether they are in any
way combined, which refers it to the 17th.

** Stigma dozcny, widiout the character
of the preceding section, for this and all the
followm ; are truly diadelphous. Very nice,
but accurate, marks distinguish the genera,
which are sufficiently natural. The style
and stigma afford the discriminative charac-
teristics oiOrobus, £.115:3; Pisum, t. 1046;
Lathyrus, t. 670, 1 108; Vicia, t. 334, 481—
483; and no less decisively in Ervum^ t. 9/0,
1223, which last genus, notwithstanding the
remark in Jussieu 360, " stigma non barbae
turn" (taken probably from no genuine spe-
cies), most evidently belongs to this section,
us was first remarked m the Flora Briiannica;
and it is clearly distinguished from all the
other genera of the section by the capitate
stigma hairy all over ; nor is any genus in
the whole Class more natural, when the hU

444 DI A DELPHI A.

therto mistaken species are removed to their
proper places. See Fl. Brit.

*** Legume imperfectly divided into two
cells, always, as in all the following, without
the character of the preceding sections. This
is composed of the singular Biserrula, known
by its doubly serrated fruit, of which there
is only one species; the Phaca, Jacq. Ic.
liar. t. 151; and the vast genus of Astra-
galus, Engl. Bot. t. 274, &c., lately illus-
trated in a splendid work by an able French
botanist, Decandolle.

**** Legume with scarcely more than one
seed. Of this Psoralen, Curt. Mag. t. 660;
the curious Sty losant lies of Swartz; the Hallia
of Thunberg ; and our own Trifolium, Engl.
Bot. t. 1770, 1048—1050, are examples.
The last genus, one of the most natural as
to habit and qualities, is extremely untractav
ble with respect to botanical characters. Some
species, t. 1047, 1340, 1769, have many
seeds in each pod ; some have not even the
capitate inflorescence made a part of the ge-
neric definition. The difficulty is lessened by
establishing Meliloius as a genus, with Jus-

DIADELPHlA. 445

sieu : but the^vhole requires to be well re-
considered ; for, if possible, so great a laxity
of definition, with such glaring exceptions,
should not disgrace any system.

***** Legume composed of single-vahed
joints, which are rarely solitary. Hedysa-
rum 9 t. 96, is the most important genus of
this section, and is known by its obtuse or
rectangular keel. Tlippocrepis, t. 31; Omi-
thopus 9 t. 369 ; ^nd Scorpiurus? known in
gardens by the name of Caterpillar, from its
worm-like pod, are further examples. Smiihia,
Ait. Hort. Ken\ t. 13, is remarkable for
having the joints of the legume connected by
means of the style, as by a thread ; the sta-
mens in 2 eqiial divisions, with 5 anthers to
each ; and a two-lipped calyx. Hedysarurn
ve$pertilionis 9 Jacq. Ic. Rar. f. 566, in some
points approaches this genus, and more cer-
tain species are possibly latent among the
numerous unsettled papilionaceous plants of
India.

****** Legume of one cell, with several
seeds. To this belong the genu3 Melilotus r
if separated from TrifoUum; the Indigofera r

446 DIADELPHIA.

several species of which are so valuable for
dyeing blue ; the handsome Robinia, Curt.
Mag. t. 311; Cytisiw, t. 176, &c; and Cli-
toria*, Ins. of Georgia, t. 18: also Lotus,
Engl Bot. t. 925, and Medicago, t. I6l6 ;
which last is justly transferred by Willdenow
from the foregoing section to this.

Papilionaceous plants are rarely noxious to
the larger tribes of annuals, though some
species of Galega intoxicate fish. The seeds
of Cytisus Laburnum have of late been found
violently emetic, and those of L&thyrffi sa-
tivus have been supposed at Florence to soften
the bones, and cause death ; we know of no
other similar instances in this Class, which is
one of the most abundant in valuable escu-
lent plants. The negroes have a notion that
the beautiful little scarlet and black seeds of
Abrus precatorius, so frequently used for
necklaces, are extremely poisonous, insomuch
that half of one is sufficient to kill a man.
This is totally incredible. Linnaeus however
asserts rather too absolutely, that " among
all the leguminous or papilionaceous tribe
there is no deleterious plant to be found."

* From KAsiw, to close or shut up, in allusion to the
situation of the wings and keel.

i

POLYADELPHIA. 447

Class 18. Poli/adelphia. Stamens united
by their filaments into more than 2 parcels.
Orders 3, distinguished by the number or
insertion of their stamens, which last par-
ticular Linnceus here overlooked.

No part of the .Linnaean system has been
less accurately defined or understood than
the Orders of the 18th Class. Willdenow,
4 aware of this, has made some improve-
ments, but they appear to me not suffi-
cient, and I venture to propose the follow-
ing arrangement.

1. Dodecandria. Stamens, or rather Anthers,
from 12 to 20, or 25, their filaments, un-
connected with the calyx. Of this the first
example that presents itself is Theobroma,
the Chocolate tree, Merian. Sarin, t. 26,
63, Lamarck Encycl. t. (335. The flowers
have not been seen fresh in Europe, and
we only know them from drawings made
in the West Indies, one of which, preserved
in the Linnaean herbarium, is my authority
for the following descriptions. The fila-
ments are inserted between the long taper-
ing segments of a 5 -cleft nectary, on its

44£ rbLYAOJBLPHZA,

outside, and each bears at ia^ summit 4
sessile, obtuse, spreading anthers. Aublet's
figure of this genus, which Schreber and
Willdenow seem to have followed, repre-
sents but 2. The fruit is perhaps most
properly a berry with a hard coat, whose
seeds, when roasted, make chocolate.
Bubroma of Schreber, Guazuma Lamarck,
t. 6*37, confounded by Linnaeus with the
preceding genus, has similar filaments, but
each bears 5 anthers ; Jussieu and Cava-
nilles say 3. The fruit is a woody capsule,
with 10 rows of perforations. Abroma,
Jacq. Hort. Vind. v. 3. t.h Miller Illusir.
t. 63, has 5 parcels of anthers, nearly
sessile on the outside of the nectary, be-
tween its obtuse, reflexed, notched lobes.
It is difficult to say how many anthers
compose each parcel, for the different ac-
counts on record are totally irreconcileable*
We have found 3 ; the drawing sent to
Linnseus represents 6 ; and Miller has a
much greater number. Perhaps they may
vary. In this uncertainty the genus in
question is best placed with its natural al-
lies in this order, with a reference to it in
italics at the end of Polyadelphia Poly an-

POLYADELPHIA. 449

dria. Its fruit is a membranous winged
capsule, opening at the top. Monsonia,
Curt. Mag. t. 73, Lamarck, U 638, re-
moved by Schreber and Willdenow to
Monadelpliia, rather, I think, belongs to
this class where Linnaeus placed it. The
5 filaments, bearing each 3 long-stalked
anthers, are merely inserted into a short
membranous cup, or nectary, for so the
analogy of the 3 preceding genera induces
us to call it; and if we refer Monsonia to
Monadelphia, we fall into the error of Ca-
vanilles mentioned p. 439- Lastly, Citrus,
the Orange, Lemon, &c, Lamarck, t. 639,
most unquestionably belongs to this Order.
Its stamens are about 19 or 20, combined
variously and unequally in several distinct
parcels ; but those parcels are inserted into
a proper receptacle, by no means into the
calyx, as the character of the Class Icosaii-
dria indispensably requires. Even the
number of the anthers of Citrus accords
better with most plants in Dodecandria
than in Icosandria, notwithstanding the
title of the latter.

'2. Icosandria. Stamens numerous, their
2 o

450 SYNGENESIA.

filaments inserted (in several parcels) into
the calyx. — To this Order Professor Will-
denow properly refers Melaleuca, Exot>
Bot. t. 34 — 36, 55, 56, which had previ-
ously stood in Polyandria, botanists hav-
ing only considered number and not in-
sert io?i in the Orders of Polyadelphia,
whence a double mistake has arisen, con-
cerning Citrus on the one hand, and Me-
laleaca on the other.

S. Polyandria. Stamens very numerous, un-
connected with the calyx. This Order
consists of several genera. The most re-
markable is Hypericum, E?igL Bot. 1. 109?
1225 — 1227? &c, whose stamens are united
into 3 or 5 parcels, corresponding with the
number of its styles. Munchhausia is a
Lagerstromia, nor does it appear to be
polyadelphous at all. Linnaeus seems to
have intended bringing Thea into this
Order.

Class 19- Syngenesia. Anthers united into
a tube. Flowers compound. Orders 5.

This being truly a natural Class, its Of«?
ders are most of them equally so, though

SYNGENESIA* 451

some are liable to exceptions, as will pre-
sently be explained.

1. Polygamic! aqualis* In this each floret*
taken separately, is perfect or united, be-
ing furnished with its own perfect stamens
and pistil, and capable of bringing its seed
to maturity without the assistance of any
other floret. The Order consists of 3 sec-
tions.

* Florets all ligulate, or strap-shaped,
called by Tournefort semiflosculous. These
flowers are generally yellow, sometimes blue,
very rarely reddish. They expand in a morn-
ing, and close towards noon or in cloudy
weather. Their herbage is commonly milky
and bitter. Leontodon, Engl. Bot. t. 510 ;
Tragopogon, t. 434, 638 ; Hieracium, t. 349?
&c; and Cichorium t t. 539? exemplify this
very natural section.

** Flowers globose, generally uniform and.
regular, their florets all tubular, 5-clcft, and
spreading. Carduus, t. 107, 6'75, 973 —
976; Onopordum, t. 977, and Arctium,
t. 1228, well exemplify this. Carlina, t. 1 144,
2 g c 2

452 SYNGENESIA.

does not so exactly agree with the above de-
finition, having a flat disk ; but its affinity
to the other genera is indubitable. Its flat-
tened disk and radiating coloured calyx seem
contrived to imitate the radiated flowers of
the following Order.

**f* pi ozcers discoid, their florets all tu-
bular, regular, crowded and parallel, form-
ing a surface nearly flat, or exactly conical.
Their colour is most generally yellow, in some
cases pink. Santolina, t. 141 ; and Bidens,
t. 1113, 1114, are genuine examples of this
section : Eupdtofium, t. 428, and the exotic
Stahelina, Dicks. Dr. PL 13, approach to
the preceding one. There is however the
most absolute difference between these two
sections, collectively, and the first ; while, on
the other hand, they have considerable af-
finity with some of the following Orders, as
will be hereafter explained.

2. Polygamia superflua. Florets of the disk
perfect or united ; those of the margin
furnished with pistils only; but all pro-
ducing perfect seed.

SYNGENESIA. 453

* Discoid, the florets of the margin being
obsolete or inconspicuous, from the smallness
or peculiar form of the corolla; as Artemisia,
Engl. Bot. t. 338, 973, 1230; Tanacetum,
t. 1229; Conyza, t. 1195; and GnapliaUum,
t. 267, 1157- In the last the marginal flo-
rets are mostly 5-cleft and tubular like the
rest, only wanting stamens. Caution is re-
quisite to detect the difference between this
section and the preceding Order.

** Ligulate, ^-lipped, of which Perdicium,
a rare exotic genus, is the only instance.

#** Radiant, the marginal florets ligulate,
forming spreading conspicuous rays ; as Bel-
lis the Daisy, I. 424 ; Aster, t. 87, a very
numerous genus in America; Chrysanthemum^
t. 601, 540; Inula, t. 1546, &c. This sec-
tion seems, at first sight, a combination of
the first and third sections of the former Or-
der, but this is chiefly in the form of its co-
rollas. It is rather an approach of that third
section towards what is equivalent to becom-
ing double in other tribes. Accordingly, the
Chamomile, A nthemis nobilis, £.980; Clirij-
santlicmum Leucanthemum, t. 601 : and

454 SYNGENESIA,

some others, occasionally have their whole
disk changed to ligulate white florets, desti-
tute of stamens, and consequently abortive.
Such are actually called double flowers in this
Class, and very properly. Many exotic spe-
cies so circumstanced are met with in gardens.
A few very strange anomalies occur in this
section, as already mentioned, p. 306, one
Sigesbeckia having but 3 stamens, instead of
5, the otherwise universal number in the
Class ; and Tussilago hybrida, t. 430, as well
as paraeloxa of Retzius, having distinct an-
thers. Nature therefore, even in this most
natural Class, is not quite without exceptions.

3. Polygamia frustranca. Florets of the
disk, as in the preceding, perfect or united ;
those of the margin neuter, or destitute of
pistils as well as of stamens ; only some
few genera having the rudiments of pistils
in their radiant florets.

This Order is, still more evidently than
the last, analogous to double flowers of
other Classes. Accordingly, Coreopsis is
the very same genus as Biclens, only fur^
nished with unproductive radiant florets.
C. Helens of Linnosus is the same species

SYNOENESIA. 455

'tis his B. cernua ; C. coronata is his jB.
f random ; and C. leucantha, B. pilosa.
Some species of Coreopsis indeed have
never been found without rays. Linnceus
expresses his difficulties on this subject in
Phil. Bot. sect. 209, but seems inclined
to unite the two genera. A similar am-
biguity occurs between Gorteria and
Atractylis, TLelhania (of the last Order)
and Athanasia, and in some degree be-
tween Centaurea, Engl. Bot. t. 278, 1678,
56, &c, and Car dims or Serratula ; only
the scales of the calyx of Centaurea ge-
nerally keep that genus distinct.

I should be much inclined to abolish
this Order. Those of its genera which
have rudiments of pistils in their radiant
florets, as Hudbeckia and Helicuiihus^
would very commodiously range with their
near relations in Polygamia supcrjlaa, nor
are we sure that such radiant florets are in
all circumstances abortive, neither qan a
student often know whether they are so
or not. It does not follow, from what has
just been observed, that the presence of
radiant florets, whether abortive or not.

456 SYNGENESIA.

can never afford a generic character, pro-
vided there be no corresponding genus
without them. This must be determined
by experience and observation. They are
indeed to be considered as a very secondary
mark, the most essential in this Class be^
ing derived from the receptacle, crown of
the seed, and calyx. These Gaertner has
illustrated with the greatest accuracy and
skill, but even these must not be blindly
followed to the destruction of natural
genera.

4. Polygamia necessaria. Florets of the
disk furnished with stamens only, those of
the margin, or radius, only with pistils; so
that both are necessary to each other. This
is well seen in the common Garden Mari-
gold, Calendula, in whose calyx, when
ripening seed, the naked and barren disk
is conspicuous. Othonna, Curt. Mag.
t. 306, ?68, Arctotis, Osteospcrmum and
Silphium, not rare in gardens, are further
examples of this Order, which I believe is
constant and founded in nature. We have
no British specimens either of it or the
following. Filago, at least as far as our

GYNANDRIA. 457

Flora is concerned, belongs to Gnaphalium.
§ee»E?igl BoU f. 946, 1193, &c.

5. Polygamia segregate SieiHeral flowers,
either simple or compound, but with united
tubular anthers, and with a partial calyx,
all included in one general calyx. Of these
the Globe-thistle, Echinops 9 and Stoebe y
with Seriphivm and Corymbium, (which
two last require to be removed hither from
the abolished Linnaean Order Syngenesis
Monogamia,) have only 1 floret in each
partial calyx ; Jungia has «?, Eh pliant op us
4, others more. In every case the partial
calyx is distinguished from the chaffy seed-
crown observable in several genera of the
other Orders, (though the latter is indeed
analogous to a calyx,) either by being in-
ferior, or by the presence of a seed-crown,
pr feathery down, besides. See Lamarck,
t. 718 — 723, where the plants in question
are well represented.

Class 20. Gynandria. Stamens inserted
either upon the style or germen. Orders 9
in Linnaeus, but some alterations concern-
ing them are necessary.

458 GYNANDRIA.

This is one of those Classes abolished by
the celebrated Thunberg, and by several less
intelligent writers who have followed him.
The reasons v?hich led to this measure appear
to have been that Linnaeus has erroneously
placed in Gynandria several plants which
have not the requisite character ; hence that
character itself has been judged ambiguous,
or not founded in nature, and the system has
been supposed to be simplified by overlooking
it. This appears to me a great mistake. The
character of the Class, taken as above, is as
evident, constant and genuine as that of any
Other in the system. No doubt can arise, if
we be careful to observe that the stamens
actually grow out of the germen or style, and
not merely out of any part that supports the
germen ; as will appear by examples.

}. Monandria. Stamen, or sessile Anther,
1 only. This contains all the beautiful and
curious natural family of the Qrchidece, or
Orchis tribe, except only Cjfpripedium^
which belongs to the next Order. I am
induced to consider the bulk of this family
as ?nonandrous, upon a careful review of

GYNANDRIA. 4.59

Professor Swartz's representation of the
subject, in his excellent treatise, just come
to my hands in English. MWTracts rela-
tive to Botany tranrfatecQtom different
Languages (by Mr. Kbnig), printed for
Phillips and Fardon, 1805. I have al-
ready, p. 272, mentioned the glutinous
nature of the pollen of these plants. This
forms yellow elastic masses, often stalked,
in each cell of the anther, and the cells are
either parallel and close together, or re-
moved from each other to the opposite
gides of the style : which serves to connect
them, just as the filament does in many
Scitamineous plants, alike therefore decided
to be monanclrous. Such a decision with
regard to those also is justified by the ana-
logy of other species, whose cells being-
approximated or conjoined, properly con-
stitute but one anther. The grand and
absolute subdivision of the Orchidete is
justly founded by Dr. Swartz, after Haller,
on the structure of the anther, whether it
be, as just described, parallel, like that of
Orchis, Engl. But. U c 22 ; Ophrys, t.65;
and Diurh, Eiot. Bot. t. 9, &c; or ver«

460 GYNANDRIA.

tied!, consisting of a moveable lid on the
top of the style, like Dendrobium, t.10 —
12 ; or ./Uflfe.9, Engl. Bot. t. 72. The
style of ^Wrchidetf has been called a
column, but I think that term now alto-
gether superfluous. It is really a style,
and the stigma is a moist shining space,
generally concave, and situated, for the
most part, in front of the style beneath the
anther. In Orchis bifolia, t. 22, and others,
it is just above the orifice of the spur.
Concerning the nectary of these plants there
has been much diversity of opinion. The
calcar, spur, in Orchis, and some other
genera, is acknowledged to be such, and
holds abundance of honey. This spur is
judged by Swartz, as well as Linnaeus, a
decisive generic mark of distinction, and it
commonly is so ; but some Indian species
brought by Dr. Buchanan prove it not to
be absolute, The remarkable and often
highly ornamented lip, considered by
Swartz as the only corolla, for he takes all
the other leaves of the flower for a calyx,
has, by Linnaeus and others, been thought,
either a part of the nectary, or, where no

GYNANDRIA. 461

spur is present, the only nectary. Nor is
this opinion so ill-founded as many bota-
nists suppose ; for the fron^K the lip evi-
dently secretes honey in fl|p/.$ (or Epi-
pactis) ovata, t. 1548, and probably in
others not yet attended to. Nevertheless,
this lip might, like the petals of lilies, be
deemed a nectariferous corolla, were it
certain that all the other leaves were truly
a calyx. But the 2 inner are so remark-
ably different from the 3 outer ones in
Ophrys, t. 64, 65, 71, 383, and above all,
in Stelis, Eivot. Bot. t. 75, that I am most
inclined to take the former for the corolla,
the latter being, according to all appear-
ance, a calyx. An insensible gradation
from one to the other, of which we have
pointed out other instances in treating of
this subject already, occurs in Diuris, t. 8,
9 ; while in some Orchidece the leaves all
partake more of the habit of a calyx, and
in others of a corolla. Even the lip in
ThcLjmitra, t. 29, assumes the exact form,
colour, and texture, of the rest of the
flower ; which proves that a dissimilarity
between any of these parts is not always to

462 GYNANDiKlA.

be expected in the family under considera-
tion. Vahl appears by the preface to his
E/iumerajAMi! ant arum to have removed
the ScitavUfite to Gynandria, because the
stamen of Canna adheres to the style.
This, if constant, could only concern that
genus, for the rest of the Order are in no
sense gynandrous.

2. Diandria. To this Order Cypripedimn,
Engl. Bot. t. 1, must be referred, having
a pair of very distinct double-celled anthers.
See Tr. of Linn. Soc. v. 1 , t. 2, 3. Here
we find Forstera, so well illustrated by
Professor Swartz in Sims and Roni^s An-
nak of Botany, i).l. 291, t.6; of which
genus Phyllachne, t. 5 of the same volume,
is justly there reckoned a species. Of the
same natural order with Forstera is Styli-
dium, but that having 4 anthers, belongs
to the fourth Order of the present Class.
Gunnera, placed by Linnaeus in Gynandria
Diandria, is not yet sufficiently well un-
derstood.

3. Triandria. Salacia, if Linnaeus's descrip-

GYNANDRIA. 463

tion be right, is properly placed here ; but
Jussieu doubts it, nor does my dried spe-
cimen serve to remove the uncertainty.
Stilago proves to be merely the barren
plant of Antidesma alexiteria, and belongs
to Dioecia ; as Sisyrinchium and Ferraria
do to Monadelphia, the tubular united sta-
mens of the two last having been mistaken
* for a solid style. Rhopium of Schreber
{Meborea of A ubiety t. 323,) seems there-
fore the only certain genus of the Order
under consideration ; unless Lamarck be
right in referring to it Jacquin's Strumpfia,
upon which I have not materials to form
any opinion. The original discoverer at-
tributes to this plant 5 stamens with united
anthers ; hence it found a place in the
Syngenesia Monogamia of Linnaeus. La-
marck merits attention, as he appears to
have had an authentic specimen. See his
t. 731.

4. Tetrandria. Nepenthes, of whose extra-
ordinary kind of leaf mention is made
p. 197, is the only genus of this Order in
Linnteus, but very erroneously placed here,

464 GYNANDRIA.

for it belongs to Dioecia Monadelphia*
The Order however must be retained for
the sake of Sty Helium, a New Holland
genus, related, as above mentioned, to
For st era. This is my Ventenatia, Exot*
Bot. t. 66, 67 ; but another genus having
previously, without my knowledge, re-
ceived the latter denomination, that of
St ■?/ Helium, under which I had, some time
ago, communicated this genus to the French
botanists*', and which they have adopted,
becomes established. See La Billardiere's
excellent work on New Holland plants,
where several species of it are figured.

5. Pentanclria. The original genera of this
Order, Ayenia, Glut a, and Passifiora,
Exot. Bot. t. C 2S, most unquestionably have
nothing to do with it, their stamens being
inserted below the germen, merely on a

* I was not aware of Loureiro's Stylidium, a plant,
according to his description, of the 7th Class; FL
Cochinck. v. 1. 221 ; but this can scarcely interfere with
ours, heing probably, as it grows about Canton, some
well-known shrub that happened to have a 7-cleft flower.
It should seem to belong to the Ruliacece, notwithstand-
ing some points in the description.

£ynandrU. 465

columnar receptacle. The learned Schreber
therefore justly removed them to the 5th
Class.

But this Order may receive a reinforce-
ment from the Linnaean Pentandria Digy-
nia. Several of the Contort a have long-
been thought to belong to Gynandria ; see
Pergularia, Ic Pich t. 16, and Andr.
>Bcpos.t. 184. In this gertus, as well as
Cynanchum and Asckpias, the pollen is
produced in 5 pair of glutinous masses,
exactly like the pollen of Orchidece, from
5 glands inserted upon the stigma, so that
no plants can be more certainly gynandrous.
Some obscurity arises from each mass of
pollen being received into a kind of bag or
cell, formed by a peculiar valvular appa-
ratus that encircles the organs of impreg-
nation, and bears a great resemblance to
filaments or stamens. The pollen however
is, in the above genera, neither attached
to, nor secreted by these cells or valves.
but by the 5 glands, each of which is dou-
ble or two-lobed, and all of them seated
on that thick abrupt angular body which
performs the functions of a stigma. Nor is
2 h

A66 gynandria.

it worth while to dispute whether this whole
body be a stigma or not, with regard to
the question under consideration, for it is
borne by the styles, above the germen, and
itself bears the anthers. I humbly con-
ceive, however, with Linnaeus and Jacquin,
that as part of it, at least, recei