SHAPE OF LEAVES 



95 



133. Decurrent 

 leaves of mul- 

 lein. 



The shape of many leaves is described in combinations 

 of these terms, as ovate -lanceolate, lanceolate -oblong. 



199. The shape of the base 

 and apex of the leaf or leaflet 

 is often characteristic. The 

 base may be rounded (Fig. 

 124), tapering (Fig. 127), cor- 

 date or heart-shaped (Fig. 139), 

 truncate or squared as if cut 

 off. The apex may be blunt or 

 obtuse, acute or sharp, acum- 

 inate or long -pointed, truncate 

 (Fig. 141). 



200 The shape of the mar- 

 gin is also characteristic of each kind of leaf. The mar- 

 gin is entire when it is not indented or cut in any way 

 (Fig. 137). When not entire, it may be undulate or wavy 

 (Fig. 126), serrate or saw-toothed (Fig. 139), dentate or 

 more coarsely notched (Fig. 

 124), crenate or round - 

 toothed, lobed, etc. 



201. Leaves often differ 

 greatly in form on the same 

 plant. Observe the differ- 

 ent shapes of leaves on the 

 young growths of mulberries 

 and wild grapes ; also on 

 vigorous squash and pumpkin 

 vines. In some cases there 

 may be simple and compound 

 leaves on the same plant. 

 This is marked in the so-called Boston ivy or ampelopsis 

 (Fig. 142), a vine which is used to cover brick and stone 

 buildings. Different degrees of compounding, even in 

 the same leaf, may often be found in honey locust and 



134. Two pairs of connate leaves 

 of honeysuckle. 



