Annual or perennial herbs, terrestrial or aquatic, usually bearing filiform root-like organs (rhizoids) at the base. Stem-like stolons arise at the base of the peduncle and bear leaves, inflorescences and bladder like traps. Leaves in terrestrial species mostly erect, entire, linear to circular; in the aquatic species usually dichotomously divided into capillary segments. Traps spherical or ovoid with a trap door or mouth and various diverse appendages. Flowers in bracteate racemes, rarely solitary, borne on capillary peduncles. Calyx lobes 2, usually accrescent. Corolla 2-lipped; upper lip 2(-3-lobed; lower much longer with a raised palate, spurred. Stamens 2. Fruit a spherical or ovoid capsule, dehiscent in various ways, rarely indehiscent. Seeds usually minute.