Plants densely to loosely cespitose; rhizomes short, no more than 10 cm. Culms sharply trigonous in cross section, (15-)25-95(-110) cm, scabrous-angled distally. Leaves: basal sheaths reddish purple; ligules as wide to slightly longer than wide; blades dark green, flat to W-shaped, widest leaves (4-)4.5-11.5(-13) mm wide, glabrous. Inflorescences 2.7-18 cm; proximal bract 9-45 cm, exceeding inflorescence; proximal 1-3(-4) spikes pistillate, erect or the proximal often spreading, (12-)15-22 mm thick, if spikes less than 15 mm thick, then usually less than 2.5 times as long as wide; terminal 1 spike staminate. Pistillate scales narrowly oblong, 3.4-11.2 × 0.5-1.1 mm, as long as or shorter than perigynia, margins often ciliate, apex truncate to retuse, erose, prolonged to scabrous awn. Staminate scales with distinct, scabrous awn, sometimes ciliate-margined. Perigynia spreading, strongly 7-12-veined, veins separate nearly to beak apex, broadly ovate, (6-)6.5-10.8 × (1.8-)2-3.5(-4.2), apex contracted; beak 2.5-5.9 mm, 0.7-0.9 length of body, bidentate, smooth, teeth straight, to 0.2-0.8 mm. Stigmas 3. Achenes yellow to brown, trigonous, papillose. Fruiting May-Aug. Wet meadows, marshes, seeps, shores of ponds, lakes, and streams, open swamp forests, ditches, mostly in acidic, often sandy soils; 0-1200 m; Nfld. & Labr., N.S., Ont., Que.; Ala., Ark., Conn., D.C., Fla., Ga., Ill., Ind., Ky., La., Maine, Md., Mass., Mich., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.; Mexico, West Indies, South America. Carex lurida is an abundant, variable, and often weedy species. A few specimens appear to be hybrids of C. lurida with C. lupulina.