Carex pachystachya

Plants densely cespitose. Culms 15-120 cm. Leaves: sheath white hyaline or green-veined, summits usually U-shaped, often prolonged to 4 mm beyond collar; distal ligules 1-2.5(-4) mm; blades 3-4(-5) per fertile culm, 10-30 cm × 1.2-4.2(-6.5) mm. Inflorescences dense or open, gold to dark brown, 0.9-2.8 cm × 6.7-16.3 mm; proximal internode 0.7-4.5(-9) mm; 2d internode 0.7-4 mm; proximal bracts usually scalelike, sometimes bristlelike, shorter than inflorescences. Spikes 3-9(-13), distinct or densely aggregated and individually indistinct, ovoid to broadly ovoid, 4.4-10 × 3.2-8.7 mm, appearing coarse-textured, base acute to rounded, apex rounded. Pistillate scales dark gold or red-brown to dark brown, usually with pale or green midstripe, ovate, 2.2-3.7(-4.2) mm, less than or equaling perigynia in length and width, margin white, 0-0.15 mm wide, apex obtuse to long-acute. Perigynia ascending to spreading, golden brown or coppery to blackish, conspicuously (0-)2-9-veined abaxially, conspicuously 0-4(-7)-veined adaxially, veins reaching top of achene, ovate to elliptic-ovate, plano-convex, 2.8-4.7(-5.1) × 1.1-2.3 mm, 0.5-0.7 mm thick, margin flat, including wing 0.2-0.4 mm wide, sometimes filled with pithlike tissue near base, ciliate-serrulate at least on distal body, occasionally with white margin, with metallic sheen; beak red-brown to black at tip, sometimes white-hyaline, cylindric, unwinged, ± entire for 0.4-0.7 mm, suture usually inconspicuous, distance from beak tip to achene 1.5-2.2(-2.8) mm. Achenes elliptic to broadly ovate, 1.2-1.9 × 0.7-1.4 mm, 0.4-0.6 mm thick. 2n = 74.

Fruiting summer. Moist to wet, open meadows, strands along lakeshores, forest edges; 0-3500 m; Alta., B.C., Sask., Yukon; Alaska, Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.; Asia (Siberia).