LEAVES AND THEIR USES 



237 



(Fig. 142). Each leaf -blade of this 

 plant is curved into the shape of a 

 pitcher which catches and holds rain 

 water. Insects, attracted by nectar 

 that is produced about the mouth of 

 the pitcher, crawl into it. They are 

 prevented from crawling back by 

 strong, pointed hairs inside, which 

 are turned downward. Finally the 

 insects are drowned in the liquid in 

 the pitcher. This liquid contains 

 enzyms, produced by some of the 

 cells that line the pitcher. The 

 enzyms digest (that is, change to a 

 soluble form) such parts of the dead 



insects' bodies as the plant can use FIG I42 _^ an m . 

 for food, and the leaf cells absorb sect-catching leaf of the 

 this dissolved food from the water, common pitcher plant 

 Pitcher plants of other species are 

 found in the southern United States, O f the leaf, 

 on the Pacific coast, and in the 

 tropical parts of 

 the eastern hemi- 

 sphere. 



The "sun- 

 dews " catch in- 

 sects in a very 

 different way. 

 The edges and 

 the upper surface 

 of each leaf bear 

 thick glandular 

 hairs (Fie i/n) ^ IG- I4 ^' Leaves of a sundew (Drosera rotundi- 



;" folia) : A, after the leaf has been stimulated by 

 Un the swollen the touch of an insect . 5> a leaf in the unst i mu . 



end of each hair lated condition. After Kerner, 



