Plants densely cespitose; rhizomes ascending to erect, reddish brown, 0-10 mm, stout. Culms 8-27 cm, scabrous distally; bases (remnants of old leaves) strongly fibrous. Leaf blades green, greatly exceeding culms, 1.4-4 mm wide, herbaceous, papillose to scabrous abaxially, papillose to scabrous adaxially. Inflorescences with both staminate and pistillate spikes; peduncles of staminate spikes 0.3-0.8 mm; proximal cauline bracts leaflike, usually shorter than inflorescences. Spikes: proximal pistillate spikes 2-3 (basal spikes 0); cauline spikes overlapping, proximal 2 separated by less than 7 mm, with 6-15 perigynia; staminate spikes 5.3-10 × 1.1-2.3 mm. Scales: pistillate scales pale to, usually, dark reddish brown to purplish brown, with similarly colored or narrow white margins, ovate to lanceolate, 2.9-3.7 × 1.2-2 mm, equaling or exceeding perigynia, apex acute to acuminate or cuspidate; staminate scales ovate, 3-4.3 × 1-1.8 mm, apex obtuse to acute or acuminate. Anthers 1.4-2.6 mm. Perigynia pale green, veinless, ellipsoid, 2.8-3.6 × 1-1.3 mm, longer than wide; beak straight, pale green, 0.7-1 mm, weakly ciliate-serrulate, apical teeth 0.1-0.4 mm. Stigmas 3. Achenes brown, ellipsoid, obtusely trigonous in cross section, 1.4-2 × 0.9-1.2 mm. 2n = 36. Fruiting early Apr-late Jun. Acidic soils of rocky, dry woods, thickets, and clearings, in partial shade of mixed hardwood-pine forests or full sun along open roadsides and clearing edges, often adjacent to streams; 10-800 m; Ont.; Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind., Ky., Mass., Miss., Mo., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Va., W.Va.