Description

Key Characters:

Growth Form: Perennials, rhizomes short, ligneous.

Stems: culms tufted, rigid, 30–90 cm tall, trigonous, the angles acute, often with minute antrorse projections.

Roots: Fibrous root system.

Leaves: Leaves simple. Leaves numerous. Blades folded to nearly flat, linear, shorter than to slightly longer than the culm, 7–9 mm wide, septate–nodulose. Apex gradually acuminate. Surfaces green, glaucous, subcoriaceous. Margins entire. Veins parallel. Sheathing; sheaths purplish brown, tinged reddish brown, septate–nodulose. Stipules absent.

Flowers: Flowers in corymbs compound, 5–15 cm long and as wide, rays 3–14, 3–12 cm long, secondary corymbs up to 3 cm long, secondary rays 1–4, up to 2.5 cm long, each one bearing a glomerule of spikelets 1–3 cm long, each glomerule dense, of 5–20 spikelets; involucral bracts 5–7, much longer than the corymb, the longest one up to 40 cm long; spikelets 8– 20–flowered, lanceolate–oblong or narrowly ovate, flattened, 6–10 mm long, 2.5–2.7 mm wide, acute, rachilla not winged; glumes pale grayish green, tinged pale yellowish brown and often red–flecked, chartaceous, spreading, oblong–elliptic, 1.5–2.2 mm long, 1–1.2 mm wide, 2–grooved, minutely reticulate, apex acute, the midnerve ± prolonged into a minute mucro. Flowers bisexual (perfect). Corolla (petals) absent. Stamens 1–2. Ovary superior; stigmas 3.

Fruit: Achenes reddish brown at maturity; oblong–ovoid to oblong–ellipsoid; trigonous; 1.2–1.5 mm long; apex apiculate. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy:

Habitat: Naturalized in disturbed; wet sites.

Elevation Range: 600–1,000 m.