Plants densely to loosely cespitose; rhizome internodes 1.2–2 mm thick. Culms dark purple-red to (3.4–)4–7.3 cm high at base, 8–65(–85) cm. Leaves: sheaths glabrous; blades green, widest blades 2.4–4(–5.3) mm wide, smooth abaxially. Inflorescences 0.094–0.94 of culm height; peduncles of lateral spikes smooth or barely scaberulous; peduncles of terminal spikes 1.6–22(–51) mm, usually barely exceeding lateral spikes; proximal bract sheaths loose, glabrous abaxially, sheath front slightly concave to slightly convex, elongated 0.1–0.6(–1.1) mm beyond apex; ligules 0.9–3.9(–6.6) mm; distal bract slightly exceeding or rarely much exceeding terminal spike. Spikes (3–)4–5(–6), distal 2–4 overlapping; lateral spikes pistillate or rarely androgynous, with 3–19 perigynia, 5–26 × 4.6–9.2 mm, ratio of spike length (in mm) to flower number = 1.4–2.2; terminal spikes 7–37(–46) × 1–2.9 mm. Pistillate scales 2.1–5.3 × 1.2–2.4 mm, margins whitish, usually with red-brown speckles, entire, apex with awn 0.2–3.3 mm, rarely awnless. Staminate scales 3.3–4.8 × 1.1–1.6 mm. Anthers 2–2.8 mm. Perigynia spirally imbricate, 52–64-veined, unwrinkled to wrinkled, narrowly ellipsoid to obovoid, obtusely triangular in cross section, (4–) 4.3–5(–5.6) × 1.5–1.9(–2.1) mm, 2.4–2.9(–3.2) times as long as wide, lustrous, base very gradually tapered, apex gradually tapered; beak absent or straight, 0–0.2 mm. Achenes broadly obovoid to obovoid, (3–)3.1–3.5(–3.7) × 1.5–1.8 mm, loosely enveloped by perigynia; stipe straight, 0.6–0.8(–0.9) mm; beak usually straight, occasionally bent 10–30°, 0.3–0.6 mm.
