Plant: perennial aquatic herb; fresh-water, usually glabrous, with thick adventitious roots; STEMS of branching rhizomes

Leaves: lanceolate to orbicular, deeply cleft, entire, pinnately veined, glabrous above and glabrous to densely pubescent below; petiole terete, flattened or winged, glabrous to pubescent

Flowers: solitary; usually floating; sepals 5-14, greenish, yellow- or red-tinged, persistent; petals numerous, inconspicuous, scale- or stamen-like, oblong to spatulate, often emarginate; stamens numerous, yellow- or red-tinged; pistils with 5-many, mostly united carpels; stigmatic disk broad, concave or flat, with 5-many rays; ovary multi-locular, each locule with numerous ovules, with anthers 1-8 mm long

Fruit: a leathery berry, ovoid to columnar, usually ripening above the water surface, with stigmatic disk dentate to entire, slightly to narrowly constricted below. SEEDS to 6 mm long, narrowly to broadly ovoid, yellow to brown, with a more or less conspicuous raphe