Slender, perennial, rhizomatous, laticiferous, acaulescent aquatic herbs, with air
canals and scattered vascular bundles. Rhizomes short, erect, villous-pubescent, bearing
flowers, leaves, vegetative buds and axillary runners. Leaves simple, stipulate, long-,petiolate, heterophyllous, submerged and erect, or floating, oblong to suborbicular,
cordate or subsagittate at base. Flowers small, solitary, usually long-pedunculate, bisexual, with spirally arranged floral appendages. Sepals 5, free, hypogynous, persistent.
Petals numerous, unequal, epigynous, free above, connate into a tube and adnate to the
ovary below, persistent; innermost ones transitional to stamens. Stamens numerous, free,
arranged on corolla tube, pendulous, each differentiated into a short constricted filament (oval in cross section) and a dorsiventrally flattened broad anther with microsporangia arranged laterally or sublaterally. Ovary 6 - 14-loculate with a cup-like depression above, formed by radiating curved stigmas; stigmatic appendages incurved, Conniving into a cone; ovules numerous in each locule, orthotropous, bitegmic, crassinucellate; placentation laminar. Fruit ripening under water into an irregularly dehiscent many-seeded berry, enclosed by and crowned with persistent calyx and corolla. Seeds spinulate, exarillate, operculate, with minute embryo, scanty endosperm and copious perisperm.
S.E. Asia, one genus and 4 species; one species in India.
S.E. Asia, one genus and 4 species; one species in India.