Carex straminiformis

Plants densely cespitose. Culms 20-50 cm. Leaves: sheaths adaxially white-hyaline, often cross-corrugated, summits U-shaped or rounded, sometimes prolonged to 2.5 mm beyond collar; distal ligules 1-2.5(-3.5) mm; blades 2-4(-7) per fertile culm, 8-25 cm × (2.5-)3-4 mm. Inflorescences dense, gold or brown, 1.3-3 cm × 12-20 mm; proximal internode 0.5-3.9(-5) mm; 2d internode 1-3(-4) mm; proximal bracts scalelike or bristlelike, shorter than inflorescences. Spikes 3-8, usually distinct, broadly ovoid, 9-12 × 6-9 mm, base rounded to attenuate, apex rounded. Pistillate scales white, gold, red-brown, or coppery, with pale to green midstripe, lanceolate to ovate, 3.2-4.8 mm, shorter and narrower than perigynia, margin white, 0-0.15(-0.3) mm wide, apex acute to acuminate. Perigynia ascending to spreading, green, straw colored, or occasionally white, 10-20-veined abaxially, conspicuously 0-12-veined adaxially, thin, broadly ovate, flat except over achene, 4-5.8 × 1.8-3.4 mm, 0.3-0.5(-0.6) mm thick, 1.7-2.3 times as long as wide, margin flat, including wing 0.4-1 mm wide, edge minutely crinkled and ciliate-serrulate at least distally; beak spreading, gold, red-brown to dark brown, sometimes white-hyaline at tip, flat, ± ciliate-serrulate, sometimes cylindric, unwinged, ± entire for 0.5-0.7 mm, abaxial suture usually inconspicuous, distance from beak tip to achene 2.2-3 mm. Achenes elliptic to broadly obovate, (1.4-)1.7-2.4 × 1-1.6 mm, 0.3-0.5 mm thick.

Fruiting summer. Rocky, gravelly soils; 1900-3800 m; Calif., Idaho, Mont., Nev., Oreg., Utah, Wash.