Culms 1.4-25 cm. Leaves: basal sheaths pale to medium brown; blades dull green to yellowish green, longer than stems, 1.3-5.4 mm wide, coriaceous, margins green, crenulate to scabrous. Lateral spikes 0-3, basal, on erect peduncles. Terminal spikes with staminate portion 2-3-flowered, 2--3.6 × 0.4-1 mm; pistillate portion 2-7-flowered. Pistillate scales green, margins (2-)2.5-6.5 mm wide, essentially concealing perigynia, apex acute, distal scales lanceolate to ovate, apex acute. Staminate scales green to pale brown, ovate to oblong, 1.9-3.5 × 0.8-1.5 mm, margins enfolding scales above, white, often with reddish brown tinge, apex obtuse. Anthers 0.9-1.3 mm. Perigynia dull green to dark olive green, ellipsoid to ovoid, 4.8-6.6 × 1.9-3.2 mm, loosely enveloping achenes, apex gradually tapering; beak 1.9-2.9 mm, smooth. Stigmas clavate, erect, shorth, thick, minutely papillose. Achenes 2.5-3.2 × 1.6-2.3 mm. 2n = 66. Fruiting spring-summer (late May-late Jul). Dry, rocky, open, or shaded slopes, ridges, and barrens, in hardwood, mixed, or coniferous forests, including pine plantations, on acidic and calcareous substrates; 200-2100 m; Alta., B.C., Man., N.B., Ont., Que., Sask.; Colo., Maine, Mich., Minn., Mont., N.H., N.J., N.Y., N.Dak., Pa., S.Dak., Vt., Wis., Wyo.
Much like no. 90 [Carex willdenowii Willd.]; main lvs 3-6 mm wide; staminate scales ca 3, the margins connate to above the middle; pistillate scales wholly green, wider than and nearly concealing the perigynia, the lower elongate and lf-like, (1.5-)2-7 cm, the upper progressively reduced but still surpassing the perigynia; perigynia 2-5, turgid, rounded-trigonous, inconspicuously nerved, 4-5.4 mm, rhombic-ovoid and obscurely beaked to subglobose or obovoid and with a conspicuous, smooth or obscurely serrulate beak to 2 mm; achene without a stylar apiculus; 2n=66. Woods and thickets; Que. to N.J., w. across the n. states to Minn., Neb., B.C., Oreg., and Utah. (C. durifolia; C. saximontana)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.