Fors. Oecon. Plantel. ed. 3, 1: 938. 1821.
Plants usually loosely cespitose; rhizomes spreading to erect, purplish brown to reddish-brown, 0–10 mm, slender. Culms arching to spreading, 5–31 cm, smooth or scabrous distally; bases (remnants of old leaves) weakly or not at all fibrous. Leaf-blades pale green, shorter to longer than culms, 0.9–2.6 (–3.2) mm wide, herbaceous, glabrous abaxially, scabrous adaxially. Inflorescences with both staminate and pistillate spikes; peduncles of basal spikes slender, elongate, erect; peduncles of distal spikes 0.6–4 (–10) mm; proximal nonbasal bracts leaflike, equaling or exceeding inflorescences. Spikes: pistillate spikes 1–4 (basal spikes 0–2); cauline spikes overlapping, separated by less than 7 mm, with 4–15 perigynia; distal staminate spikes 3.1–11.3 × 0.7–2.7 mm. Scales: pistillate scales pale to dark reddish-brown, with narrow to broad white margins, ovate, 2–2.8 × 1–1.8 mm, shorter than perigynia, apex obutse, acute, or acuminate (cuspidate on some basal spikes); staminate scales ovate, 2.4–4 × 1–1.9 mm, apex acute to acuminate. Anthers 1.2–2.5 mm. Perigynia yellowish green to grayish green, veinless, globose to obovoid, 2.3–3.1 × 1–1.4 mm, as long as or longer than wide; beak often bent, pale green, occasionally with reddish-brown tinge, 0.4–0.8 mm, ciliate-serrulate, apical teeth 0.1–0.2 mm. Stigmas 3. Achenes brown, obovoid, obtusely trigonous in cross-section, 1.3–1.6 × 1–1.4 mm.
Alta., B.C., Man., N.B., N.S., N.W.T., Ont., Que., Sask., Yukon, Alaska, Calif., Colo., Conn., Idaho, Maine, Mass., Mich., Mont., N.H., N.Y., Oreg., Utah, Vt., W.Va., Wash., Wis., Wyo.
Varieties 2 (2 in the flora).