INTRODUCTION TO BOTANY. Vv 
39. Leaves are more or less distinctly marked by veins, which, starting from the 
stalk, diverge or branch as the blade widens, and spread over it in various patterns. 
These veins represent the woody and vascular system (170) of the leaf. The 
principal ones, when prominent, are often called ribs or nerves; the smaller branches 
then retaining the names veins or veinlets. When one principal nerve runs direct 
from pe = oe the apex of the leaf, it is called the midrib. When several 
start from the stalk, diverge slightly without branching, and converge again towards 
the summit, they are said to be parallel, although not ‘nathisanadlcaiy so. The ve- 
nation is said to be reticulate or netted, when the veins and veinlets are inosculated 
together like the meshes of a net : such veins are said to anastomose together. 
40. The lobes, segments, or leaflets of leaves are, 
pinnate, when several succeed each other on each side of the midrib or com-- 
mon-petiole (compared to the branches of a feather). A pinnately-lobed 
leaf is called pinnatifid. A pinnately-lobed or divided leaf is called lyrate, 
when the terminal lobe or segment is very much larger and broader than 
the lateral ones ; rwncinate, when the lateral lobes are curved backwards 
— the base of the leaf ; pectinate, when the lobes resemble the teeth 
of a comb. : ; 
palmate or digitate, when several div from the same point ; compared to 
the fingers of a hand. A leaf with palmate lobes is called palmatijid. 
ternate, when three only start from the same point. A leaf with ternate 
lobes is called tvijid. A leaf with 3-leaflets, like a trefoil, is trifoliolate ; 
and when the common petiole is prolonged beyond the insertion of the 
lateral leaflets, carrying forward the terminal one a short distance, it is 
pinnately-trifoliolate or wnijugate. 
pedate, when the division is at first ternate, but the two outer branches are 
forked, the outer one of each fork again forked, and so on, and all the 
branches start from near the base ; vaguely compared to the foot of a 
bird. A leaf with pedate lobes is called pedatifid. : 
41. The teeth, lobes, segments or leaflets may be again and again toothed, lobed, 
divided, or compounded. Some leaves are 3-4 or many times divided or com- 
pounded. In the latter case they are termed decompound. 
42, The number of leaves, or of their parts, is expressed adjectively by the fol 
lowing numerals, derived from the Latin :— 
uni-, bi-, tri-, quadri-, quinque-, sex-, septem-, octo-, novem-, decem-, &c., multi-, 
sn ae 3-, 4, i, 6-, a 8, o-, 10-, many-, 
ase oer Sg ta np aaa Pea : ae 
us, 
wni-dentate, bi-dentate, multi-dentate, mean 1-toothed, 2-toothed, many- 
toothed. 
bi-fid, tri-fid, multi-fid :—2-lobed, 3—-lobed, many-lobed. 2 ee ae 
uni-foliolate, bi-foliolate :—with one leaflet, with two leaflets, &e. 
uni-jugate, bi-jugate, multi-jugate, with one, two, or many pairs of pinne, or 
eaflets of a pinnate leaf. — ee os 
43, Leaves, or their parts, or any other flat organs of plants are, : 
linear, when long and narrow, at least 4-5 times as long as broad, with the 
two margins nearly parallel ; : 
subulate, or awl-shaped, when long and narrow, tapering to a sharp point ; 
pungent, when the point is rigid and piercing. 
lanceolate, when three or more times as long as broad, broadest just below 
the middle, and tapering towards the summit ; ‘ 
cuneate, when broadest above the middle, blunt at the apex, and tapering to 
the base; compared to an inverted wedge ; flabelliform or fan-shaped, is 
broadly cuneate and rounded at a ne mer a 
_ deltoid, equilateral-triangular or shaped like a Greek A : when app! 
tooth of a calyz, the base of the triangle is supposed © rest on the 
calyx-tube. : 
spathulate, when the broad near the top is short, and the narrow, taper- 
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