Description

Key Characters:

Growth Form: Aquatic perennial herbs, free–floating or sometimes rooting at the nodes in mud.

Stems: Stems or stolons arising from a mass of fibrous or feathery roots.

Roots: Fibrous root system.

Leaves: Leaves simple. Alternate, floating or immersed; all basal except 1(2) cauline. Blades obovate, cordate, ovate, orbicular, linear, sagittate, or lanceolate. Margins entire. Veins acrodromous. Long-petiolate, petioles sheathing and tubular and auriculate at base. Petioles long, swollen or inflated in lower part, the inflated part filled with aerenchyma; sheathing and tubular. Stipules present.

Flowers: Flowers in short spikes, panicles, or racemes subtended by a single reduced leaf or 1–2 bladeless sheaths; terminal. Flowers bisexual (perfect). Perianth in two series bilabiate, the tube funnelform, the lobes broad, thin, slightly unequal. Stamens 6, all similar, upper ones included, lower ones exserted. Ovary superior, 3-celled; ovules numerous.

Fruit: Capsules. Seeds numerous; ovoid; longitudinally ribbed.

Ploidy:

Habitat: Aquatic.

Elevation Range: