Aquatic plants with floating stems. Leaves either exclusively submerged, multipartite with filiform segments or partly submerged with filiform segments partly floating, lobate to slightly dissected into wider segments. Flowers small, solitary on long peduncles (reflexed in fruit), white with a yellowish claw or yellowish as a whole, with sepals and petaloid petals. Petals with a basal, open nectar pit. Stamens numerous. Carpels nut-l ike, arranged in a subglobose to elongate head, without a keeled margin, transverse-rugose.