Plants loosely cespitose; rhizomes horizontally spreading, reddish brown to dark brown, (10-)40-100 mm, slender. Culms 10-45 cm, smooth to weakly scabrous distally; bases (remnants of old leaves) slightly fibrous. Leaf blades green, 0.5-3.6 mm wide, herbaceous, papillose to scabrous abaxially, papillose to scabrous adaxially, blades of distal cauline leaves well developed. Inflorescences usually with both staminate and pistillate spikes; peduncles of staminate spikes 0.1-7.5 mm; proximal cauline bracts leaflike, usually shorter than inflorescences. Spikes: proximal pistillate spikes 1-3(-4) (basal spikes 0, rarely 1); cauline spikes overlapping or separated, with (3-)4-13 perigynia; staminate spikes 8-24 × 1.3-4 mm. Scales: pistillate scales dark reddish brown, with narrow white margins, ovate, 2-4 × 1.3-2.8 mm, equaling perigynium body, apex obtuse or acute to acuminate; staminate scales elliptic to ovate, 2.9-5.3 × 1.1-1.9 mm, apex obtuse or acute to acuminate. Anthers 1.8-4 mm. Perigynia pale green, veinless, obovoid, 2.2-3.4 × 1.1-1.5(-1.7) mm; beak straight, pale green, 0.5-0.9 mm, weakly ciliate-serrulate, apical teeth 0.1-0.4 mm. Stigmas 3. Achenes dark brown, obovoid, obtusely trigonous in cross section, 1.3-2.3 × 0.9-1.4(-1.6) mm. 2n = 36.
Stems (1-)2-5 dm, tufted in small to large, basally fibrillose clumps and also with long rhizomes; lvs 1-3 mm wide, shorter than the stems in tall plants; staminate spike terminal, 1-2.5 cm; pistillate spikes 1-3, sessile or short-pedunculate and loosely ascending, borne fairly close to each other and to the staminate spike, but not closely crowded, typically short-oblong, to ca 1.5 cm; lowest bract 1-3 cm, ±leafy, surpassed by the staminate spike; pistillate scales castaneous to stramineous, longer or shorter than the perigynia; perigynia 2.6-4.5 mm, short-hairy, 2-keeled and with several evident to obscure facial nerves, the body subglobose above the contracted base, abruptly prolonged into the sharply bidentate beak 0.2-1 mm; achene rounded-trigonous. N.Y. and s. Me. to Va. (and in the mts. to N.C. and Tenn.), w. to s. Sask., B.C., Wash., Calif., Oreg., and N.M. Two vars. with us, a third on the Pacific coast.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Common in northern Indiana, less frequent southward, and rare or absent from the southernmost counties. Like Carex communis it is a species flowering in early spring, found in similar localities but preferring somewhat more open habitats and generally in more sterile soils. It usually forms rather extensive colonies, sometimes comprising the dominant floor cover in open oak woods.