Rhizomes 2–5 mm diam. Culms sharply trigonous, sides deeply concave throughout to rarely nearly flat, 0.4–2.5 m × 3–10 mm. Leaves ca. 3, basal, less than 1/2 culm length; sheath fronts not pinnate-fibrillose; blades 1–3, V-shaped near base, otherwise laterally flattened-trigonous in cross section; distal blade 0.2–1.5 times as long as sheath, 25–200 × 2–8 mm. Inflorescences capitate or very rarely with 1 branch to 5 mm; proximal bract usually erect, resembling leaf blade, 1–6 cm. Spikelets 2–20, 5–15 × 3–5 mm; scales bright orange- to red- or purple-brown to straw-colored, often partly translucent, usually clearly lineolate-spotted, broadly ovate, 2.7–4 × 2–3 mm, smooth or awn sparsely spinulose, margins deciduously ciliolate, flanks of proximal scale often with several ribs, apex rounded to acute, notch 0.1–0.4 mm deep, awn not contorted, 0.2–0.6 mm. Flowers: perianth members (2–)5–6(–7), yellow-brown, bristlelike, slender to stout, often unequal to equaling 1/2 achene body, retrorsely spinulose; anthers 1.5–3 mm; styles 2-fid or 2-fid and 3-fid. Achenes brown when ripe, thickly plano-convex or unequally biconvex or compressed obtusely trigonous, obovoid, 1.8–2.8 × 1.3–2 mm; beak 0.1–0.3 mm. 2n = 78.