SPECIAL FORMS OF LEAVES 



253 



Pitcher plants are found, usually in swamps, both in the 

 northern and southern United States. (See Figure go.) 

 The southern pitcher plant produces a sweet 

 liquid {nectar) at the mouth of the pitcher ; 

 it is quite similar to the nectar which at- 

 tracts insects to flowers. If the insect goes 

 beyond the mouth of the pitcher, it rarely 

 if ever gets out again. Just beyond the 

 rim there is a surface so smooth that even 

 a fly slips on it; it seems to be glazed. 

 If the insect slips on this smooth place, it 

 finds itself in the water which is just 

 beyond. The wetness of its wings prevents Fig. go.— A leaf of 



the pitcher plant 



it from flying out, and stiff, downward- (Sarracenia). 



pointing hairs, as well as the very smooth 



space, keep it from crawling out. It drowns. 

 The other type is well illustrated by a 



famous plant called Venus's-flytrap. This 



plant has been found only in certain swamps 



of North Carolina. (See Figure gi.) It captures insects 



by the sudden closure of 

 the trap part of the leaf. 

 This part bears sensitive 

 hairs, and the trap is 

 sprung, like a steel trap, 

 when an insect disturbs 

 these hairs. Another some- 

 what similar insect-catch- 

 ing arrangement is that of 

 the sun-dew, a swamp plant 

 which is found in various 



Fig. 91. — A rosette of leaves of the . 



Venus's-flytrap (Dionea). parts of the United States. 



Usually these 

 pitcher leaves are 

 partly filled with 

 water into which 

 insects crawl or 

 fall. 



