Description

Key Characters:

Growth Form: Perennials with short and sometimes slightly thickened rhizomes clothed with brown or reddish brown basal sheaths and their fibrous remnants.

Stems: culms 15–60(–90) cm tall, 2–6 mm in diameter near base, trigonous, smooth.

Roots:

Leaves: Leaves simple. alternate Blades stiff, linear, shorter than to longer than the culm, 3–12 mm wide. Margins entire. lower sheaths tinged reddish brown. Stipules absent.

Flowers: Flowers in inflorescences umbelliform, simple or compound, dense to lax, 2–5 cm long, 3–12 cm wide, rays 6–8, 1–4 cm long, spikes solitary or with 1–3 lateral spikes, cylindrical to oblong-cylindrical, 2–4 cm long, 8–10 mm wide, moderately densely bearing numerous spikelets; involucral bracts 4–8, spreading, the lower 2–5 longer than the inflorescence, the lowest up to 15 cm long and ca. 3 mm wide; spikelets 6–8–flowered, elliptic to oblong–elliptic or oblong-lanceolate, somewhat flattened, turgid with obtuse angles, 3–6 mm long, 1.8–2.3 mm wide, rachilla narrowly winged; glumes pale reddish brown, reddish brown, or brown, membranous to thin and chartaceous with hyaline margins, tightly imbricate, broadly ovate, 2.5–3.5 mm long, 1.8–2 mm wide, 9–11 veined, midnerve often prolonged into a minute mucro, apex rounded. Flowers bisexual (perfect). Corolla (petals) absent. Stamens 3. Ovary superior.

Fruit: Achenes oblong–ellipsoid; trigonous; 1.2–1.5 mm long; 0.5–0.7 mm wide. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy:

Habitat: Occurring on ridges; 'a'a lava; in gulches; dry to mesic forest; and subalpine forest.

Elevation Range: (60–)250–1980 m.