Hist. Pl. Guiane, 321. 1775.
Herbs, young vegetative parts often with rust-colored pubescence, barely mucilaginous. Leaves submersed and floating; petiole short to long. Submersed leaves: blade in 3-7 dichotomously [trichotomously] branched, linear segments. Floating leaves: blade terminal, linear-elliptic [broadly elliptic], margins entire or notched at base, appearing only during flowering, inconspicuous [more evident in C. aquatica, a tropical species]. Flowers: sepals 3, petaloid, obovate; petals 3, oval, with proximal, yellow, nectar-bearing auricles, base clawed; stamens 3-6, opposite petals; pistils [1-]2-4, simple, 1-locular; ovules [1-]3[-5]; stigma capitate. Fruits elongate-pyriform, tapered to apex. Seeds ovoid [somewhat globose], tuberculate. x = 13.
Mostly tropical regions, Western Hemisphere.
Species 5 (1 in the flora).