118 ESSENTIALS OF BOTANY 
condition is permanent. 
In other plants, as in Indian 
corn, the leaf rolls up when the weather is very dry and 
unrolls again when it receives a better supply of water. 
Fic. 83. Common Pitcher-Plant 
(Sarracenia purpurea). 
At the right one of the pitcher-like leaves 
is shown in cross-section. 
and so on, belong to this class. 
138. Fleshy Leaves. — 
Many xerophytes and a 
still larger proportion of 
halophytes have thick, 
fleshy leaves, sometimes 
thick at the base and 
tapering to a point often 
nearly cylindrical in 
form. The common 
portulaca, the so-called 
“ice-plants,” and the 
century-plant offer fa- 
miliar examples of fleshy 
leaves. Leaves of this 
form stand exposure to 
the hottest sunshine, 
even when the plant is 
scantily supplied with 
water. 
139. Leaves of Meso- 
phytes. — The great 
majority of foliage 
leaves, such as those of 
most common garden 
herbs, grasses, clovers, 
They are neither remark- 
ably thick nor thin, expanded nor scanty in surface, and 
they show no such special adaptations as rolling up to 
avoid the parching effect of excessive sunshine. 
