DEVELOPMENT OF PLANTS 



399 



287, C). These plants are largely perennial, with underground 

 stems in the form of bulbs or rhizomes. This feature adapts 

 many of them to dry and steppe regions, from which source many 

 of our cultivated lilies have been obtained. It will be seen that 

 this habit of storing food in underground stems enables these 

 plants to develop their leaves, flowers and fruit during the short 



Fig. 287. The fawn lily, Erythronium americanum: A, habit of the plant. 

 B, the bulb, showing the origin of the stem and leaves shown in A; r, run- 

 ners that penetrate the soil forming new bulbs at their tips. C, pistil of 

 three carpels, at the right the fruit, a capsule, opening to scatter the seeds. 



rainy season, after which the entire aerial portion withers away 

 and their life lies dormant in the buried stems. This habit is 

 equally serviceable if these plants come into competition with 

 larger forms, as in forests where plants with bulbs and rhizomes 

 may complete their annual growth before the grosser vegetation 

 that would crowd them out is fairly started (see page 42) . 



(a) The Fawn Lily, Erythronium americanum. — This species 

 may be examined as typical of the order (Fig. 287). This plant 

 has received the atrocious name of adder's tongue, which is of- 



