INTRODUCTION 



the stem. This angle is called the axil of the leaf, from a 

 Latin word meaning the arm-pit, and such a bud is, therefore, 

 termed axillary. 



Many quick-growing stems, especially among Grasses and the 

 Umbelliferous family (p. 191), have hollow or fistular internodes. 



Stems may be underground or aerial, the chief forms of under- 

 ground stems being the tuber, the corm, the bulb, the rhizome, 

 and the sucker. 



The tuber is a fleshy rounded structure giving off few, if any, 



Portion of a branch with leaf / 

 and bud b. 



Scaly bulb of the Lily : a, shortened stem ; 

 b, fibrous roots ; c, scales ; d, flowering 

 stem. 



roots, and bearing scattered buds, being made up of several inter- 

 nodes, as in the Potato and the Black Bryony. 



The corm is a short, thick, solid stem, generally of one inter- 

 node, giving off roots below, and bearing buds on its upper sur- 

 face, as in the Snowdrop, Crocus, Lords-and-Ladies, &c. 



-I 



Portion of rhizome, r, of the Solomon's seal ; b 1 , terminal bud ; b, a branch ; 

 s, s, scars produced by the decay of old branches. 



The bulb is a short stem made up of many unelongated inter- 

 nodes and enclosed in numerous fleshy leaf-scales. When these 

 are narrow and overlap like tiles, as in Lil.es, the bulb is called 

 scaly ; when they are sheathing and concentric, as in the Onion, 

 tunicate. 



The rhizome, or rootstock, is an elongated stem bearing scale- 



b2 



