Culms trigonous, 15–90 cm, scabrous-angled. Leaves: sheath with apex of inner band hyaline, not or barely thickened, concave; ligules 0.7–2.5 mm; blades 1–3.2 mm wide. Inflorescences 1–5 cm; spikes 4–12, ascending, ovate; proximal spikes pistillate; middle spikes often staminate; terminal spike pistillate or androgynous. Pistillate scales reddish brown with green center and hyaline margins, ovate, 2.8–5.5 mm, shorter than to equaling perigynia, apex acute to acuminate. Perigynia thin-margined, wingless, lanceolate to ovate, 3.9–6.5 × 1.4–2.4 mm; beak 1.2–2.7 mm. 2n = 70.