48 ELEMENTS OF BOTANY. 
ment during the winter (or the rainless season, as the case 
may be) to secure rapid growth during the active season. It is 
Fic. 33.— Rootstock of a Sedge. 
The young, advancing shoot is seen at 
the left ; in the centre is a cluster of 
leaves rising above ground; further 
to the right similar clusters would be 
found springing from the same root- 
stock. 
72. Condensed Stems. — 
The plants of desert regions 
require above all protection 
from the extreme dryness of 
the surrounding air, and, 
usually, from the excessive 
heat of the sun. Accordingly, 
many desert plants are found 
quite destitute of ordinary 
foliage, exposing to the air 
interesting to notice that 
nearly all of the early- 
flowering herbs in tem- 
perate climates, like the 
crocus, the snowdrop, the 
spring-beauty, the tulip, 
and the skunk - cabbage, 
owe their early-blooming 
habit to richly stored 
underground stems of 
some kind, or to thick, - 
fleshy roots. 
Fic. 34. — Roots, Rootstocks, and Leaves 
of Iris. 
only a small surface of green rind. In the melon-cactuses, 
Fig. 38, the stem appears reduced to the shape in which the 
