Description

Key Characters:

Growth Form: Perennials with thick horizontal rhizomes.

Stems: Culm (stem) solitary, 1–3 m tall, terete (cylindrical), often bearing extra–vaginal shoots at lower nodes.

Roots:

Leaves: Leaves simple. Leaves cauline. Blades thick, coriaceous, linear, flat, 60–90 cm long, 8–15 mm wide. Apex caudate, 3–sided, gradually tapering. Margins strongly serrulate–scabrous. Sheathing; sheaths loose, shorter than the internode. Stipules absent.

Flowers: Flowers in inflorescences 30–90 cm long, with 5–9 corymbs, these terminal and lateral, nearly contiguous or the lower ones well-spaced, each one 4–8 cm long and as wide, the peduncle and rays flattened; bracts leafy, sheathing at base, much longer than their subtending corymb; spikelets rusty brown, congested in globose heads of 4–12, each one ovoid–ellipsoid or broadly so, ca. 4–9 mm in diameter, ca. 3 mm long, ca. 2 mm wide; glumes broadly ovate, abruptly contracted to the obtuse or subacute apex. Flowers bisexual (perfect) or staminate. Calyx (sepals) absent. Corolla (petals) absent. Stamens 2. Ovary superior; stigmas 3.

Fruit: Achenes somewhat drupaceous; brown; ovoid–globose; 1.8–2 mm long; apex apiculate; base rounded. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy:

Habitat: Occurring in wet sites such as marshes; seeps; along streams; and in fresh water or brackish ponds.

Elevation Range: 0–90(–640) m.