Amer. J. Sci. Arts, ser. 2, 4: 22. 1847.
Plants cespitose or not, short-rhizomatous. Culms solitary or not, erect, (25–)40–90(–110) cm. Leaves 6–12; basal sheaths purplish red; sheath of distal leaf 0–1.5(–2.5) cm; ligules rounded, 2.5–6 mm; blades 12–34 cm × 4–11 mm. Inflorescences 2.5–17 cm; peduncles of proximal pistillate spikes 0.7–3.5 cm, basal 2 peduncles 1–4(–12) cm apart; peduncle of terminal spike 0.5–6 cm; bracts leafy, usually sheathless, blades 8–26 cm × 2–7 mm. Spikes: proximal pistillate spikes 1–2(–3), densely (4–)8–35-flowered, separate to aggregated, globular, 2.5–4.2 × 2.6–4.1 cm; terminal staminate spike 1, 0.5–6.5 cm × 1–4 mm. Pistillate scales 1–5-veined, lanceolate-ovate to ovate-orbicular, 4–11 × 2–4.2 mm, apex obtuse to awned, awn to 7 mm, rough. Anthers 3, 2.5–4.8 mm. Perigynia radiating out in all directions, strongly 16–25-veined, rhombic-ovoid, 12.5–20 × 4–8 mm, base cuneate, dull, glabrous or, sometimes, hispidulous; beak poorly defined, 1.5–3 mm. Achenes sessile, ellipsoid to obovoid, faces convex, angles not thickened, 3.3–4.8 × 2.6–3.7 mm; style withering.
Phenology: Fruiting May–Aug.
Habitat: Mesic to wet deciduous forests, forest openings, usually on fine alluvial or lacustrine deposits, riverbottoms
Elevation: 0–500 m
Ont., Que., Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., Md., Mass., Mich., Minn., Miss., Mo., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Vt., Va., Wis.
Pubescence on the perigynia of Carex grayi is most frequently found in plants from the Midwest and South.