Carex alata Torr.

Plants densely cespitose. Culms 30–140 cm. Leaves: sheaths adaxially conspicuously green-veined nearly to collar, narrow hyaline band or sharp Y-shaped region at collar, adaxially firm, sometimes papillose, summits U-shaped; distal ligules 2.8–8 mm; blades 3–7 per fertile culm, 11–50 cm × 2.5–6 mm. Inflorescences dense or open, pale green or brown, 2–6.5 cm × 7–20 mm; proximal internode 3–13 mm; 2d internode 4–10 mm; proximal bracts scalelike with bristle tips shorter than inflorescences. Spikes 3–11, distant, distinct, ellipsoid to ovoid, 6–20 × 4–9 mm, base rounded or short-acute, apex broadly acute to obtuse. Pistillate scales white-hyaline or tan, with green midstripe extending to tip, lanceolate, 2.8–3.5(–3.8) mm, shorter or longer and much narrower than perigynia, apex firm, acuminate or awned to 0.8 mm. Perigynia ± spreading, light or golden brown, faintly 3–8-veined on each face, obovate, flat except over achene, 4–5.5 × 2.5–3.8 mm, 0.4–0.5 mm thick, margin flat, including wing 0.8–1.5 mm wide; beak light brown at tip, flat, 0.85–2.2 mm, ciliate-serrulate, abaxial suture with light brown margin, distance from beak tip to achene 1.8–3 mm. Achenes oblong, 1.7–2 × 0.9–1.1 mm, 0.3–0.4 mm thick. 2n = 74.