A carnivorous, annual plant (genus Utricularia) found in fresh water or wet soil, which is not clearly divided into root, stem, and leaves, lacks roots but bears erect shoots growing from an underwater or underground stolon. Only the flowers rise clear of the surface. Leaf shoots arising from the stolon bear bladder traps, called utricules, that capture prey, terrestrial species feeding on single-celled organisms, aquatic species on invertebrates, tadpoles, and juvenile fish. There are about 220 species found worldwide.