OUTLINE OF STRUCTURAL BOTANY 19 
1. The general outline of the leaf nearly or quite complete. 
General form rounded, broader than long, the posterior parts 
extending into two rounded lobes, anti med (Fig. 15) 
Reniform 
Several principal veins radiating in all directions, the leaf 
stem inserted in the midst of the blade. Shield-shaped 
GHIiSmECO en aaitee it Ces iaal st | Sane em ea la te bo) Peltate 
2. General outline cut into deep divisions by deficiency of tissue 
between the principal veins, forming separate leaflets (Fig. 
35) SC Close acl gens. sh A) eee alumate-leaved 
Brincipaly VEINS o CHIgseas)) 6 8. = « - ees Lovlovate 
Principal veins eaGHior o4) 25 % . 2 Weems se tve-loped 
In these pinnately cleft leaves the intervening tissue is somewhat 
or largely wanting but in certain leaves this absence of intervening 
tissue is carried to the extent that the segments or lobes appear 
like quite perfect and independent leaves. An important difference 
will however be observed between such a group of apparently per- 
fect leaves and a really perfect leaf. 
If we separate by force a perfect leaf at the base of the leaf-stalk 
from the branch, it falls as a single blade as it does also in autumn 
by ripening. But if we separate the base of the leaf-stalk of one 
of these groups the whole group falls as did in the other case the 
single leaf blade. 
These groups of leaflets, all attached to a common leaf-stalk or 
petiole are known as Compound Leaves and a few forms are shown 
by the following table. 
If the number of leaflets is reduced to two the leaf is . . Binate 
If there are three leaflets arranged in a palmate form the leaf is 
Aaldesconpe ternate (Hig; 33)) 2°. 2 = ce ZOOlULe 
If there are more than three leaflets, all arising at the end of the 
leaf stem, as in that of the Horse Chestnut, it is Hand-shaped 
(CNIS 687: ar ‘ »- . . . Palmately Compound 
But if the leaflets are eR er ae each side of a common leaf- 
stalk or petiole the leaf is (Fig. 35) - . Pinnately Compound 
If the number of leaflets is exactly the same on each side of the 
leaf stem and there is not an odd one at the end, the leaf is 
SMCMIES Li ts) Goss sh He) ‘s) cro) eh oe @ 4) Osis w VEN Pinnate 
But if there is an odd leaf at the end it is « e« »« Odd Pinnate 
In the description of plants the point or apex of the leaf often 
forms an important feature for differentiation. 
