52 THE GROWTH AND PARTS OF PLANTS 
The short, flattened underground stem of the spring 
crocus is called a.corm. ‘This lives for one year. 
In spring it sends up a single flower stem, followed 
by narrow leaves. Young corms are formed as 
buds on the upper surface of the larger one; in this 
way the young corms 
as they are developed in 
succession draw nearer 
to the surface of the soil. 
Other corms are the 
cyclamen, gladiolus, etc. 
‘To see how corms differ 
from bulbs, cut one open. 
It 1s a solid, fleshy stem, — 
sometimes with loose, — 
scale-like leaves on the 
outside. 
storehouses which are 
partly stem, partly root, 
are found in the pars- 
nip, beet, turnip, radish, ete. The upper part, where 
the crown of leaves arises, is the stem, and the lower 
part 1s root. Such a tuber is sometimes called a crown 
tuber. 

Fic. 81. Corm of crocus. 
Food is stored in rootstocks, or rhizomes, also, and in 
the stems of trees and shrubs. But the kinds enu- 
merated above show some of the results which the 

