PITCHER PLANTS 



63 



40. Pitcher Plants (Fig. 24).— There are several genera of plants 

 that have pitcher-like leaves. Sarracenia purjmrea, which occurs in 

 peat bogs, is our commonest native pitcher plant. It produces a 

 cluster of radical, pitcher-shaped leaves, with a wing along one side 

 and a rounded arching hood at the upper end. The leaves are 

 usually attractively colored, yellowish-green and purple, and 10 to 

 20 cm. long. In June it sends up a flowering stem, 15 to 30 cm. high, 

 bearing a single, large, deep purple flower. The leaves of Sarracenia 

 are practically always partly filled with water, probably caught by 

 them during rains. Entrance to the pitchers is easy and insects 

 often go in, perhaps merely by chance or perhaps attracted by the 

 bright colors. Once in, however, it is almost impossible for an insect 



Fig. 24:.— Sarracenia minor. A pitcher plant. (Photograph by B. W. Wells.) 



to crawl out because of the numerous hairs near the entrance which 

 point downward. The insects, therefore, sooner or later, get into 

 the water and drown. Xo protein-digesting enzymes have yet been 

 found in the pitchers of Sarracenia but it is believed that the plant 

 absorbs the products of decay of the insects and that the symbiosis 

 is thus of the same type as that of other insectivorous plants. 



It has been shown that at least four kinds of insects and several 

 protozoa live normally in the water in the ])itchers of Sarracenia 

 lyurpurea. In some species of Sarracenia frogs are often found resting 

 in the pitchers and catching such insects as enter. Also, spiders 

 sometimes spin webs across the mouths of pitchers for the purpose of 

 catching insects. These relationships are comparable to a squirrel 



