Description

Key Characters:

Growth Form: Perennials with short, woody rhizomes clothed with dark reddish brown or purplish brown scales and their fibrous remnants.

Stems: culms stout, 50–130 cm tall, 5–16 mm in diameter near base, trigonous, smooth.

Roots:

Leaves: Leaves simple. Leaves several. Blades, linear, as long as or slightly longer than the culm, 8–15 mm wide, coriaceous. Margins entire. Sheathing; sheaths dark reddish brown. Stipules absent.

Flowers: Flowers in inflorescences umbelliform, compound or partially compound, moderately dense, 5–18 cm long, 7–25 cm wide, rays 6–12, spreading, 3–16 cm long, once branched, each branch with 2–4 secondary rays, spikes cylindrical to oblong–elliptic, 2.5–4 cm long, 1.2–2 cm wide, densely bearing numerous spikelets, bracteoles setaceous, shorter than to as long as the subtending lateral spikes; involucral bracts 5– 10, the lower ones much longer than the inflorescence and up to 12 mm wide; spikelets 6–8–flowered, widely spreading to slightly reflexed, linear-lanceoloid, subterete, slightly turgid, 10–16 mm long, 1.5– 2.5 mm wide, rachilla broadly winged; glumes green and often tinged pale yellowish brown, chartaceous with hyaline upper margins, oblong-lanceolate or oblong–elliptic, 4.5–5.5 mm long, 1.5–2.5 mm wide, laxly imbricate, suberect but those in upper part of spikelet weakly spreading, 7–nerved or 9–nerved, midnerve prolonged into a minute recurved mucro. Flowers bisexual (perfect). Corolla (petals) absent. Ovary superior; styles 5–6 mm long.

Fruit: Achenes oblong–ellipsoid; trigonous; 1.7–2 mm long; ca. 0.8 mm wide. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy:

Habitat: Occurring in mesic to wet forest; often associated with waterways.

Elevation Range: 850–1,280 m.