120 



BOTANY AND PHARMACOGNOSY. 



Modified Leaves, Leaves are variously modified and 

 serve for otlier purposes thau those already described. They may 

 be fleshy iu character and serve as storehouses for nutritive mate- 

 rial, as the seed-leaves of the oak, or they may serve for the stor- 

 age of water, as in Agave and Aloe (Fig-. 130). In some in- 

 stances, particularly when situated near the flowers, they lose 



Fig. 78. Group of transplanted wild plants showing variation in form of leaves. 

 A. Cinnamon fern (Osmunda cinnamomea) showing sporophylls (fertile leaves) and a cluster 

 of pinnatifid sterile leaves, the pinna^ being linear-lanceolate and deeply pinnatifid; B, 

 wild ginger (Asarum caMadewse) showing basal, reniform, long-petiolate leaves with cordate 

 base and slightly pointed apex; C, young hickory (Hicoria ovatd) showing the odd-pinnate 

 (imparipinnate), 5- to 7-foliate leaves; D, temate, decompound leaf of Virginia grape fern 

 (Botrychium virginianum); E, digitately compound leaves of cinquefoil {Potentilla). 



their green color, as in the dogwood, skunk cabbage and others. 

 In other cases they are modified so that they serve as a trap for 

 insects, as in species of Sarracenia and Drosera (Fig. yj). The 

 petiole may become enlarged and perform the functions of the 



