Plants cespitose, short-rhizomatous. Culms 18-80 cm. Leaves 2.5-11.5 mm wide, sparingly scabrous. Spikes 3-7(-9), erect; lateral spikes pistillate with few staminate flowers at base and rarely also at apex, narrowly elliptic, 12-50 × 7-13 mm; terminal spike usually staminate, sometimes gynecandrous, pistillate, or abortive, 6-45 × 2-6 mm. Pistillate scales narrow, with indistinct body, 3.6-9(-11) × 0.1-0.4 mm, apex with long, scabrous awn exceeding perigynium. Staminate scales loosely to irregularly imbricate with tips spreading, linear, 4.3-15 × 0.3-0.8 mm, apex with long, scabrous awn. Perigynia horizontal, 3.5-6 × 1.4-2.6 mm, minutely pustulate; beak 1.3-2.2 mm, smooth. Achenes obovoid, sides strongly concave, 1.4-2.1 × 1-1.4 mm, less than 2 times as long as wide; style deciduous, straight or sinuous. Fruiting summer. Wet meadows and woods, muddy margins of lakes and ponds, roadside ditches; 0-1500 m; Ont.; Ala., Ark., Del., D.C., Ga., Ill., Ind., Iowa, Kans., Ky., Md., Mich., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Va., W.Va. Carex frankii and the similar C. aureolensis are two of the most easily recognized species of sedge; they are identified by the approximate, erect pistillate spikes and the long-awned pistillate scales that exceed the perigynia bodies.