Plants colonial; rhizomes long-creeping. Culms lateral, trigonous, 20–80(–100) cm, scabrous-angled. Leaves: basal sheaths reddish purple, bladeless, apex of inner band glabrous; ligules 1.5–14 mm; blades green, M-shaped, 2.8–8.5 mm wide, glabrous. Inflorescences 4.5–23 cm; proximal (1–)2–3(–4) spikes pistillate, ascending; distal spikes erect; terminal 1–3 spikes staminate. Pistillate scales lanceolate to ovate, apex acute to acuminate-awned, glabrous, scabrous-ciliate apically. Perigynia ascending to spreading, 16–22-veined, broadly ovoid to broadly ellipsoid, 4.5–6.5 × 2–2.9 mm, cellular details and veination clear, sparsely short-pubescent; beak 1.2–2 mm, bidentulate, teeth straight, 0.5–0.8 mm.