Culms trigonous in cross section, 40–80 cm. Leaves: basal sheaths reddish purple, inner bands slightly fibrillose with age; sheaths pubescent, at least at apex of inner band; ligules 2–9 mm; blades 2.5–6 mm wide, finely spreading-pubescent or glabrous, not papillose abaxially. Inflorescences 15–50 cm; spikes erect or ascending; proximal (1–)2–3 spikes pistillate; terminal 1–4 spikes staminate. Pistillate scales narrowly ovate, apex acute to acuminate, scabrous-awned, scabrous near midrib, otherwise glabrous. Staminate scales lanceolate to narrowly ovate, apex obtuse to acuminate, awnless, glabrous or sparsely ± appressed-pubescent near apex. Perigynia 12–18-veined, 4.8–6.5 × 1.4–2.4 mm, sparsely to densely pubescent; beak 1.4–2.6 mm, pubescent, teeth spreading, (0.4–)0.6–1.4 mm.

Fruiting Jun–Sep. Wet meadows, lakeshores, open, moist forests along streams; 1200–1900 m; Calif., Idaho, Nev., Oreg.