Enum. Hort. Berol. Alt. 2: 380. 1822.
Plants loosely cespitose; rhizomes horizontally spreading, pale brown to reddish brown, (5–)20–80 mm, slender. Culms 7–55 cm, scabrous distally; bases (remnants of old leaves) fibrous. Leaf blades pale to dark green, 0.7–3.6 mm wide, herbaceous, papillose to scabrous abaxially, papillose to scabrous adaxially, blades of distal cauline leaves poorly developed. Inflorescences with both staminate and pistillate spikes; peduncles of staminate spikes 0.7–13 mm; proximal nonbasal bracts leaflike, shorter than inflorescences. Spikes: proximal pistillate spikes 1–3 (basal spikes 0); cauline spikes overlapping or somewhat separated, with (2–)3–13 perigynia; staminate spikes 8–22.5 × 1.4–4.6 mm. Scales: pistillate scales pale or usually dark reddish brown, with narrow white margins, ovate to lanceolate, 2.7–4.3 × 0.8–2.4 mm, apex acute to long-acuminate; staminate scales obovate to lanceolate, 3.7–6.1 × 1–1.4 mm, obtuse to acute or acuminate. Anthers 1.9–4.6 mm. Perigynia yellowish green to pale olive, veinless, obovoid, 2.7–4.6 × 1.2–1.7 mm, as long as wide; beak straight, pale green to olive, occasionally with reddish brown tinge near apex, 0.9–1.6 mm, weakly ciliate-serrulate, apical teeth 0.1–0.6 mm. Stigmas 3. Achenes dark brown, obovoid to globose, obtusely trigonous in cross section, 1.3–2.2 × 0.9–1.6 mm.
N.B., N.S., Ont., Que., Conn., Ga., Ky., Maine, Mass., Mich., Minn., N.C., N.H., N.J., N.Y., Pa., R.I., S.C., Tenn., Va., Vt., Wis.
Varieties 2 (2 in the flora).