Carex arapahoensis Clokey
Family: Cyperaceae
Arapaho Sedge
Carex arapahoensis image

Plants densely cespitose. Culms 20-30 cm. Leaves: sheaths white-hyaline, summits usually U-shaped; distal ligules 1-2(-2.5) mm; blades 3(-5) per fertile culm, 10-40 cm × 2.2-3.2 mm. Inflorescences dense or sometimes open proximally, brown or purplish, 1.2-2(-2.5) cm × (8-)12-18 mm; proximal internode 1.5-3.5 mm; 2d internode 0.5-2.5 mm; proximal bracts bristlelike, shorter than inflorescences. Spikes 4-5, densely aggregated, usually at least proximal 1 distinct, obovoid, 9-12 × (5.5-)7-9 mm, base rounded or attenuate, apex rounded or acute. Pistillate scales red- or purple-brown to dark brown, sometimes gold above the middle, sometimes with paler midstripe, ovate to broadly ovate, 4.3-5.6 mm, shorter than or equaling perigynium beaks, equaling or narrower than perigynia, margin white-hyaline, green, or gold 0.15-0.3 mm wide, apex usually acute. Anthers long-persistent. Perigynia appressed to ascending, usually dark brown, often green or gold distally and at margins, veinless or conspicuously 3-6-veined abaxially, inconspicuously veined adaxially, broadly obovate to broadly ovate, flat except over achene, 4-5.5 × 2-2.7 mm, 0.25-0.4(-0.5) mm thick, margin flat, including wing 0.4-0.6 mm wide, ciliate-serrulate at least on distal body; beak purplish or brown to red-brown, white-hyaline at tip, cylindric, unwinged, entire for 0.5-1.3 mm from tip, abaxial suture with conspicuous white margin, distance from beak tip to achene (1.9-)2.2-2.9 mm. Achenes obovate or ovate, 1.6-2.1 × 1-1.4 mm, 0.3-0.5 mm thick.

Fruiting late summer. Dry mountainsides, high meadows; of conservation concern; 3400-4000 m; Colo., Utah, Wyo.