24 « ■ B O T 
when the ftem is armed with flrong fliarp prickles; as the 
bramble. Spinovs, armed witli thorns or fpines; as the 
hawthorn, floe, See. Urcns, or flinging, when armed with 
flings ; as the common nettle. Stipulate, when fuppOrted 
with leafy props on each tide the flem ; as the everlafling 
pea; and this item, from its flipulate leaves, is alfo termed 
membranaceous. Bnlbifcrovs, the ftem-bearing fmall bulbs 
at the axillas of the leaves; as the bulb-bearing lily. The 
mvricated flem is reprefented at fig. 20 ; the lanatcd, or 
‘Ethiopian (age, at fig. 21; the hifpid, or lafeinated teafel, 
at fig 224 the acu/eated, or bramble, at fig. 23 ; and the 
kulbiferous, or bulb-bearing lilv, at fig. 24. 
VI. The composition. This is'termed Enodis, when 
compofed or made up without joints; as the bulrufh. 
Simplex, or Ample, when the trunk rites uniform and re¬ 
gular to the top ; as in flitchwort. SimpliciJ/imus, very fim- 
ple, when it has few or no branches; as dog’s mercury. 
Intire, when the flem is undivided ; as in birthwort. Ar¬ 
ticulate, when the trunk is compofed of many pieces or 
joints; as the Indian fig. Proliferous, when the flem fends 
forth branches only from the apex of the (hoots; as the 
Scotch fir. Dichotomies, or forked, branching always into 
two parts or arms; as the trunk of the white milletoe. 
Brachiate, or branching oppofite, the upper pair eroding 
the next below ; as in yellow clulia. Subramous, the flem 
throwing out but few lateral branches; as lizard’s tail. 
Ramous, throwing out many lateral branches; as the flock 
Jul)-flower. Ramocijjimus, very branchy, and growing out 
without order in all directions ; as in moll trees. Virgated, 
having many (tender twigs ; as in draw berry-blite. Pani- 
culated, when the branches are varioufly fubdivided; as 
in the wild oat. Fafigatcd, the branches a riling front a 
center to an equal height; as tooth-leaved androface. 
Patcnd, having numerous fpreading branches ; as in fen¬ 
nel. Divaricate, the branches forming an obtufe angle 
from the trunk; as in the coffee-tree. The articulated 
trunk, or Indian fig, is (hewn at fig. 2 ; ; the dichotomns 
Item, or white milletoe, at fig. n; and the divaricate, or 
coffee-tree, at fig. 26. 
VII. Rami, the branches forming a part of the flem. 
They are termed Alternate, when they come out (ingle one 
above another, following in gradual order ; as tiie wolf'si 
bane, or monk’s-hood. Djlich, in two rows, when the 
branches grow out in a horizontal direction ; as in poly¬ 
podium, or fern. Sparfed, or fcattered, when they come ' 
out irregularly; as in butcher's broom. Conjert, when the 
branches are crowded clofe together; as in cyprefs. Per. 
ticilate, the branches furrounding the trunk like the rays 
or (pokes of a wheel; as in the great water-plantain. Co- 
arElate, the branches (hooting up perpendicularly clofe to¬ 
gether; as laurus-tinus. Divergent, the branches growing 
out far from the trunk, and fpreading every way from the 
fame center; as the Arabian coffee. Deflexed, when bend- 
iug downwards archways ; as the weeping willow. Reflex, 
when turning upwards towards the trunk ; as yellow clulia. 
Rctrofex, when bending back towards the trunk ; as tiie 
buckthorn. Ruinate, when (hooting out roots from the 
branches for props or fupports ; as the Bengal fig. The 
dijlich ranti of the fern, are fliew'ii at fig. < 5 ; (he fulcrate, 
at fig..3 ; and the divergent, at fig, 26, of the above-men¬ 
tioned plates. 
Of the LEAVES. 
The leaves of plants confifi of the fame fubflancc with 
that of the trunk. They are full of nerves or woody por¬ 
tions, running in ail direftions, and branching out into 
innumerable (mali threads, interwoven with the paren¬ 
chyma, like fine lace or gauze. The pulpy or parenchy¬ 
matous part conlifls of very minute fibres, wound up into 
fmall cell;; or bladders, which are of various (izes in the 
(ante leaf. All leaves, of' whatever figure, have a mar¬ 
ginal fibre, by which all the reft are bounded. The par¬ 
ticular fliape of this fibre determines the figure of the leaf. 
The veflels of the leaves have the appearance of inofcula- 
ting; but, when examined by the microfcope, they are 
found only to be interwoven, or.laid along each other. 
A N Y, 
What are called air-vejfls, or thofe which carry no fap,’ 
are vifible even to the naked eye in fome- leaves. When a 
leaf is (lowly broke, they appear like fmall woolly fibres, 
connected to botli ends of the broken piece. 
Linnaeus confiders the leaves as the mufcles or organs of 
motion in plants; other writers call them the organs by 
which perfpiration and infpiration are performed. Some 
plants have very thick flefiiy leaves, whole pulpy fubftance: 
is always moift : thefe are fuel) as. naturally grow upon dry 
barren rocks, and are generally natives of warm countries,' 
which, as they can draw in very little nourifhment from 
the earth, perfpire only in a fmall quantity. The leaves 
of (ucli plants have a thin compact (kin,over their fur-face, 
with minute pores, which prevent the defeending moiflure 
from penetrating into their fubftance and deftroying them. 
The (ante flrudlure is alfo obfervable in the leaves of thofe 
trees and (limbs, which retain their verdure all the year; 
and they are known to imbibe and perfpire little moiflure 
in companion with the deciduous trees and flirubs :< more¬ 
over, their nutritive juices'are of a* oily exterior in their 
own quality, which fecures them from the froftv Plants', 
in general are known to receive and tranfpire more, in 
equal time, than large animals ; hence it appears that the 
leaves'are neceflary to preferve tlve plant both in health 
and life. It has been found by accurate calculation, and 
repeated experiments, that a plant of the fun-flower re¬ 
ceives arid perfpires in twenty Tour hours, levcnteen times 
more than a man. 
It is certain that no plant, to which nature has allotted 
leaves, can live without them; but will certainly die if 
they are pulled off as foon as they appear. This confirms 
the theory of the circulation tlnougli their innumerable 
pores and veflels. The leaves of rue feem full of holes, 
like a honey-comb ; all the kinds of St. John's wort appear 
likewife (tuck full of pin-holes to the naked eye, but the 
microfcope difeovers, that the places where rhefe holes 
feem to be, are really covered with a very thin and white 
membrane. The under (ide of the herb mercury looks as 
if rough-caff with (ilver, and all the ribs arc full of white, 
round, tranfparent balls, faftened by filken filaments, like 
fo many grapes. A fage-leaf appears like a rug, or fliag, 
befet with tufts of flitter thrums, and embellilhed with fine 
round cryftal beads, or pendants, faftened by (lender foot- 
(ialks. The under fide of a rofe-leaf, and particularly that 
of the fweet-briar, appears diapered with (ilver. Every 
one knows, that the leaves of flinging nettle are thick fet 
with fliarp prickles, which penetrate the (kin when touched, 
and oceafion heat, pain, and ('welling. Thefe fymptoms 
were imagined formerly to be owing to the prickles being 
left in the wound; but the microfcope difeovers fomething 
much more wonderful in this plant, and fliews that its 
prickles are formed for a&ing, in the fame manner as the 
(tings of animals; for every one of them is found to be a 
rigid body, hollow, and terminating in a very fine point, 
with an opening near its end. At the bottom of this prickle 
there lies a pellucid bag, containing a limpid liquor, which, 
upon the leaft touching of the prickle, is injected through 
the (kin, and produces pain and irritation by the pungency 
of its falts. See Raker on the Microfcope, p. 239. T he figure 
of the leaves of plants may be reprefeuted by holding one 
in the fmoke of refin, camphor, a candle, See. whereby the 
leaf acquires a blacknefs, which, when preffed on white 
paper, give-, the exact fize, fliape,. and particular ramifi¬ 
cations, of the fibres! This method may be of life to bo- 
tanifts, when they hav.e no (kill in drawing. See Boyle’s 
Works, abr. voi. i. p. 132. 
The flruflure and diverfity of leaves, have given occa- 
fiem to their being.divided into three dalles; vi ■&', finple, 
compound, and determinate. 
L Simple Leaves _Thefe are fitch a$ have only a 
(ingle leaf on a petiole; but differ in refped to circum- 
feription, angles, finufes, apices, margin, fii perfidies, and 
fiibftance ; by wjiicli properties' their characters are re- 
fpe&ivcly diftinguilhed and known. Circumscription 
implies the form of the circumference of leaves, when 
1 there 
