Bladderwort
Bladderwort, an insect-devouring plant that lives in water. The threadlike leaves have small, gas bladders that float the plant. On the underside of each bladder is a kind of trap door that opens to admit insects and water. Insects trapped inside are digested to provide food for the plant.
The common bladderwort is found in ponds and ditches all over the north temperate zone. It has yellow flowers about one-half inch (1.3 cm) long that bloom in a cluster projecting above the surface of the water. The plant is sometimes grown in aquariums as a novelty. Some tropical species have large, handsome flowers that resemble orchids. The plant has no roots.
The common bladderwort is Utricularia vulgaris of the bladderwort family, Lentibulariaceae.