Carex assiniboinensis W.Boott.

Plants densely cespitose, also producing long-arching stolons that root at the tip and form new plants. Culms dark maroon at base; flowering stems 35–75 cm, longer than leaves at maturity, 0.5–0.8 mm thick, glabrous or minutely scabrous on angles, especially within inflorescence. Leaves: basal sheaths maroon, bladeless, glabrousl; others grading from maroon to green on back, pale hyaline on front; blades flat, 1–3 mm wide, glabrous on adaxial surface, often strigose on abaxial surface, margins and midribs of abaxial surface scabrous at distal end. Inflorescences: peduncles of lateral spikess 20–60 mm, glabrous; peduncle of ternimal spike 40–60 mm, glabrous or minutely scabrous on angles; proximal bracts much shorter than inflorescence; sheaths 15–25 mm; blades 1.5–2.2 mm wide. Lateral spikes 2–5, pistillate with fewer than 10 perigynia attached 3–15 mm apart, 1 spike per node, well separated, erect or drooping, linear, 5–30 × 3–5 mm; distal spikes sometimes staminate and shorter than terminal spike. Terminal spike staminate, 11–30 × 1.5–3 mm. Pistillate scales pale hyaline, often partially suffused with chestnut brown, with narrow green midrib, lanceolate to oblong, shorter than mature pergiynia, apex cuspidate or acuminate with serrulate green awn 1–3 mm, glabrous. Perigynia green, at least body maturing to yellow, 2-ribbed but not obviously otherwise veined, except sometimes near base, tightly enveloping achene, lance-ellipsoid, 5–6.5 × 0.8–1.8 mm, cartilaginous, base with stipe 0.5 mm, apex tapering gradually to beak, short-pubescent; beak oblique to minutely toothed, 2.5 mm. Achenes stipitate, 1.8–2.5 × 0.7–1 mm, stipe adnate to thickened perigynium base, breaking from achene at maturity. 2n = 32.