Annual or perennial acaulescent aquatic herbs with submerged corm or rhizomatous stem. Leaves alternate, simple, floating, cordate, peltatc, linear to orbicular with sagittate to cordate base, long petioled. Flowers solitary, usually large. Sepals 4, adnate to ovary, usually green. Petals many, often gradually passing into staminodes and stamens. Stamens many (20-700), free or adnate to the petals. Carpels 8 or more, syncarpous or partially united, ovary superior to subinferior, many-Jocular, stigmas separate or united into a disc with radiating rays. Fruit a many seeded, irregularly dehiscent, berry. Seeds with or without aril.
A small family with 6 genera; represented in Pakistan by 2 genera and 6 species.
Acknowledgements: We are grateful to Prof. C.D.K. Cook and Dr. M. Wolf (Botanisher Garten und Institut fur Systematische Botanik der Universitat Zurich, Switzerland) for going through the manuscript and offering valuable suggestions. The financial assistance received from the United States Department of Agriculture under P.L. 480 with the coordination of Pakistan Agricultural Research Council, Islamabad is thankfully acknowledged.