Description

Key Characters:

Growth Form: Perennials with very short rhizomes.

Stems: culms tufted, erect, 25–60(–125) cm tall, slender, trigonous, rigid, 2–4–nodose.

Roots:

Leaves: Leaves simple. Leaves basal, a few cauline and well-spaced. Blades linear, 1.5–3.0 mm wide, flat. Apex acute to acuminate, scabrous. Margins scabrous. Veins parallel. Sheaths 5–9 cm long, tightly surrounding the culm; ligule rusty brown, short, membranous, truncate. Stipules absent.

Flowers: Flowers in inflorescences of 3–5 anthelate partial panicles, these solitary or paired, suberect on exserted peduncles, loosely bearing 1–9 clusters of spikelets; bracts longer than the subtending panicle, shortly sheathing at base, bracteoles setaceous to scale-like; spikelets broadly lanceoloid, weakly laterally compressed, 7–8 mm long, 2–2.5 mm wide; glumes 5–8, brown to yellowish brown, the middle 2–5 flower–bearing, (1)2 of them perfect, ovate–oblong, membranous, apex acuminate, the flower–bearing ones 5–6 mm long. Flowers all bisexual (perfect) or sometimes distalmost staminate. Perianth bristles 6, filiform, 4–5.5 mm long, minutely scabrous in upper part. Corolla (petals) absent. Stamens 3. filaments slightly longer than nutlet and style base; anthers linear. Ovary superior, obovoid; style base slightly shorter than the achene, up to 2 mm long, conical, gradually tapering from base to a filiform style; stigmas 2.

Fruit: Achenes brown; somewhat glossy; obovate; 2–3.7 mm long; ca. 1.8 mm wide; biconvex; edges subacute; the sides weakly transversely wrinkled with longitudinally oblong epidermal cells. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy: 2n = 48*

Habitat: Occurring in open; wet sites in pastures; wet forest; and bogs.

Elevation Range: (150–)550–1,750 m.