Syn. Pl. Glumac. 2: 226. 1855.
Culms densely tufted, ascending, lax or, occasionally, decumbent, 13–78 cm × 0.8–1 mm. Leaves: basal sheaths purple or purple tinged; sheaths 2–42 mm; blades ascending or lax, erect, green or yellow-green, midrib developed adaxially, 2 lateral veins abaxially, 19–38 cm × 1–5 mm, blades of overwintering leaves smooth. Inflorescences: peduncles proximal pistillate spikes to 11 cm, distal spike sessile; staminate spike 0.5–10.6 cm. Bracts 0.5–11.2 cm × 0.5–4 mm, angles of bract sheath denticulate; bract blade of distal lateral spikes linear, narrower than spikes, not concealing them; widest bract blade of distalmost lateral spike 0.5–3.4 mm wide. Spikes (3–)4(–5) per culm; lateral spikes 5–27 × 3–4 mm; internode between proximal scales in proximal spike 1.1–3.2(–4.8) mm; terminal spike linear, 11–21 × 1–2.2 mm. Pistillate scales 2.8–3 × 1–1.2 mm, apex acute to aristate, awn to 1 mm. Staminate scales 3.5–4 × 1.2–1.5 mm, margins hyaline, purple-brown or brownish purple tinged, apex acute. Anthers 2.6–3 mm. Perigynia 4–12 per spike, closely overlapping, aggregated, ascending, conspicuously (22–)25–32-veined, elliptic-obovate, 2.8–3 × 1.5–1.8 mm, 1.8–2.7 times long as wide; beak abruptly bent, 0.2–0.8 mm. Achenes obovoid, 2.6–2.8 × 1.3–1.6 mm. 2n = 33, 38, 40.
Phenology: Fruiting spring.
Habitat: Moist to dry deciduous or mixed deciduous-evergreen forests or woodland edges in partial shade, frequently on limestone or chalk, on clay or marl soils, stream bottoms or on steep slopes
Elevation: 0–600 m
Ont., Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Ky., Md., Mass., Mich., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., Tenn., Tex., Va., W.Va., Wis.