Any of about 120 widespread species of terrestrial and aquatic carnivorous plant s of the genus Utricularia (family Lentibulariaceae).
They are characterized by small hollow sacs (bladders) that actively capture and digest tiny animals that touch them, including insect larvae, aquatic worms, water fleas, and other small swimmers. Closely related to the bladderworts are the butterworts ( Pinguicula ), 35 species of land plants that capture insects by means of sticky glands on the leaf surfaces.