STEMS 



77 



which they bear are rudi- 

 mentary leaves and buds. 



Bulbs, whether coated 

 like those of the onion or 

 the hyacinth (Fig. 47), or 

 scaly like those of the 

 lily, are merely very short 

 and stout underground 

 stems, covered with closely 

 crowded scales or layers 

 which represent leaves or 

 the bases of leaves (Fig. 48). 



The variously modified 

 forms of underground 

 stems just discussed, illus- 



Fm. 44.— lioots, BootetockB, and 

 Leaves of Iris. 



trate in a marked way the storage 

 of nourishment , during the winter 

 (or the rainless season, as the case 

 may be) to secure rapid growth dur- 

 ing the active season. It is inter- 

 esting to notice that nearly all of 

 the early-flowering herbs in temper- 

 ate climates, like the crocus, the 

 snowdrop, the spring-beauty, the 



FiQ. 45. — Bootstock of Cala, 

 dium (Colooasia)* 



b, terminal bud ; b', buds ar- 

 ranged in circles where bases 

 of leaves were attached ; s, 

 scars left by sheathing ba^es 

 of leaves. 



