Description

Key Characters:

Growth Form: Fronds free-floating on water surface, 2–5 or sometimes more cohering in groups connected by elongate stipes.

Stems: The paired "leaves" are actually modified stems.. Lower surface usually reddish, reniform to obovate or orbicular.

Roots: With 2–18 fascicled roots.

Leaves: Leaves absent. Stipules absent.

Flowers: Flowers usually 3 in each pouch, 2(3) staminate and 1 pistillate in 1–2 lateral pouches on either side of the basal end of the frond, enclosed in a spathe. Flowers unisexual. Calyx (sepals) absent. Corolla (petals) absent. Stamens 2, 4-locular. Ovary superior; ovules, (1)2(4).

Fruit: Fruit indehiscent; opening by bursting. Seeds longitudinally ribbed and transversely striate or smooth; with a spongy outer layer.

Ploidy:

Habitat: Aquatic.

Elevation Range: