Description

Key Characters:

Growth Form: Glabrous, aquatic or semiaquatic perennial herbs, free–floating or rooted in substrate.

Stems: Stems sympodial, each branch terminating in an inflorescence, ± from rhizomes.

Roots: Fibrous root system.

Leaves: Leaves simple. Leaves distichous or spirally arranged, in a basal rosette or some cauline, floating or submerged. Margins entire. Veins acrodromous. Petioles sometimes inflated, sheathing and tubular. Stipules marcescent.

Flowers: Flowers in terminal racemes, spikes, or panicles, or sometimes solitary, inflorescences subtended by a usually bladeless sheath. Flowers bisexual (perfect), actinomorphic or irregular. Perianth petaloid, (4)6-lobed, the lobes all similar, in 2 series, usually connate at base to form a perianth tube. Stamens (3)6, in (1)2 whorls, rarely only 1 and with 2 staminodes; filaments distinct, adnate to perianth tube; anthers dithecal, opening by longitudinal slits or rarely by terminal pores. Ovary superior, usually 3-carpellate, 3-celled, placentation axile, sometimes 1-celled and placentation parietal; ovules numerous, sometimes only 1 and pendulous, anatropous; style slender; stigmas 1 or 3, terminal.

Fruit: Loculicidal capsules or sometimes dry and indehiscent. Seeds numerous in capsular fruit; 1 in indehiscent fruit; longitudinally ribbed; with copious starchy; mealy endosperm with an outer aleurone layer.

Ploidy:

Habitat: Aquatic.

Elevation Range: