52 



STEMS 



the world, since there are many places where it can nourish 

 while ordinary plants would be destroyed. The bitter dandelion, 

 which is almost uneatable for most animals on account of its 

 taste, which lies too near the earth to be fed upon by grazing 

 animals, and which bears being trodden on with impunity, is a 

 type of a large class of hardy weeds. 



The plants incorrectly called " stemless," like the dandelion 

 (Fig. 43) and some violets, are not really stemless, but send out 



FIG. 46. Rootstock of 

 caladium (Colocasia) 



b, terminal bud ; &', buds 

 arranged in circles where 

 bases of leaves were at- 

 tached ; 5, scars left by The dark tuber in the middle is the one from which 



FIG. 47. Part of a potato plant 



sheathing bases of leaves 



the plant has grown 



their leaves and flowers from a very short stem which hardly 

 rises from the surface of the ground. 



66. Underground stems. Stems which lie mainly or wholly 

 underground are of frequent occurrence and of many kinds. 

 Some of the simplest kinds are called rootstocks. Familiar ex- 

 amples are those of some mints, of bloodroot, of Solomon's seal, 

 and of many grasses, sedges, and ferns. The real nature of the 

 creeping underground stem is frequently shown by the pres- 

 ence upon its surface of many scales, which are reduced leaves. 



