210 BLADDEEWORT FAMILY 



leaves bear a great number of tiny inflated sacs — a pecu- 

 liarity that is recorded in both the generic name and the 

 common name. These bladders, which are thought to be 

 metamorphosed leaflets, are so constructed that the small 

 valve which closes the only opening yields readily to pres- 

 sure from without, and minute water creatures, bent on 

 solving the problems of their universe, must needs push 

 against this closed door. Who knows but good food may 

 lie beyond? Good food there is when the insect has en- 

 tered, but he himself is the food ! The valve that opened 

 so easily to admit him can never be swung outward. He 

 is a prisoner in a dungeon, and is grewsomely surrounded 

 by the skeletons of his fellows who have entered before him, 

 their soluble parts having passed into the plant through 

 the peculiarly specialized absorption cells within the blad- 

 ders. In one small bladder the remains of no less than 

 twenty-four minute water creatures have been counted. 



Aquatic bladderworts have the habit of remaining out 

 of sight during a part of their existence, and rise to the 

 surface of the water only for their blossoming season. The 

 species shown in the illustration, U. inflata, develops radi- 

 ating, air-filled floats that hold upright the slender stalk 

 of yellow flowers, and are suggestive of large spiders 

 spread out on the water. This species is common in shal- 

 low water, as are other bladderworts without floats. 



Not all bladderworts lead an aquatic life : several species 

 grow in wet sand, and their bladder-bearing leaves are 

 much reduced or lacking. Of these the tiny U. suhulata 

 is widely distributed in low pinelands, and in spring the 

 larger U. cornuta is often so abundant that its flowers 

 encircle pineland ponds with broad rings of gold. Leaves, 

 when present, in these species are small and grasslike, 

 but are so fugacious that they are seldom seen. 



The flowers of all show a characteristic two-lipped form, 

 with a small spur below which is either pendent or is 

 pressed closely to the lower lip. 



