Plants densely cespitose. Culms 14-89(-101) cm × 0.3-1.1 mm wide, smooth or papillose. Leaves: ligule on distal leaf 0.9-2.2 mm, as long as wide; blades 0.6-4.2 mm wide, widest blade 2.4-4.2 mm wide. Inflorescences 12-56 mm; proximal internode 6-34 mm; proximal bracts 6-49 mm, awn 7-46 mm; spikes (2-)3-5, longest ones 2-5, usually gynecandrous; proximal spikes with 1-2 staminate and (5-)7-12 pistillate flowers, 5.2-11(-13) × (2.1-)3.7-6.9 mm; terminal spikes usually with 1-3(-5) staminate and (7-)9-13(-16) pistillate flowers, 6.8-13 × 3.8-8.1 mm. Pistillate scales with colorless or stramineous margins, 3-4.5 × 1.6-2.2 mm, body 2.8-4.2 mm, apex acuminate to short-awned, awn to 0.6 mm. Staminate scales with colorless or stramineous margins, 3-5.3 × 1.2-1.6 mm, apex acute to acuminate or occasionally short-awned to 0.3 mm. Anthers (1.8-)1.9-2.2 mm. Perigynia erect to ascending, green to pale brown, 0-5-veined abaxially, usually veinless adaxially, narrowly ovate, 4-4.9(-5.2) × 1.3-1.5(-1.6) mm, 2.9-3.8 times as long as wide, apex gradually tapering; beak 1.4-2.1 mm, 0.32-0.4 times as long as perigynia, margins serrulate, apex entire or bidentulate, teeth to 0.2 mm, 0-0.05 times as long as perigynia. Stigmas 1.9-2 mm. Achenes 1.8-2.2 × 1.2-1.5 mm wide, 1.3-1.8 times as long as wide.
Much like no. 58 [Carex bromoides Willd.]; main lvs 2-3+ mm wide; spikes pale green or silvery, the lower one often remote and conspicuously surpassed by a subtending bract; pistillate scales largely hyaline or scarious and whitish or light brown, with firmer, greenish, sometimes shortly excurrent midrib, often wholly covering the body of the perigynium, but shorter than the beak; perigynia mostly (5-)10-25, lance- elliptic to rather narrowly elliptic, 4-5.5 mm, a fourth to a third as wide, faintly nerved or nerveless on both sides; achene broad, ±orbicular-obovate, 2-2.5 mm; 2n=54. Woods; Lab. and Nf. to Mack. and B.C., s. to Pa., Mich., Io., Ariz., Calif., and Mex. Our plants are var. deweyana; two other vars. are more western.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.