Plants colonial, long-rhizomatous, vegetative shoots widely scattered and inconspicuous from deep rhizomes. Culms 15-60 cm, usually scabrous distally. Leaves: proximal sheaths with blades, brownish, 1.5-5 mm diam.; ligules 0.4-3.6 mm, 0.4-1.2 times wider than long; blades gray-green, flat, 7-15 cm × 2-5(-7) mm, folded near bases, margins often revolute, herbaceous. Inflorescences 4-25 cm, 1-1.6 times as long as proximal bracts; proximal bract 2.5-20 cm, sheath 0.5-4 cm, blade 2-16 cm; pistillate spikes ovoid to cylindric, 6-37 × 3.5-8 mm; lateral spikes erect or ascending on stiff peduncles. Pistillate scales purple tinged or brown, apex awned or obtuse. Perigynia ascending to spreading, densely arranged, yellow-green to brown, 2.3-5 × 1.25-2.5 mm, minutely papillose; beak minute, bent. Achenes light to dark brown, 2.7-4 × 1.7-2.2(-2.5) mm. Fruiting late spring-early summer. Calcareous prairies, fens, cedar glades, open woodlands, moist depressions; 50-2400 m; Man., Ont., Sask.; Ala., Ark., Ariz., Ga., Ill., Ind., Iowa, Kans., Ky., Mich., Minn., Miss., Mo., Nebr., N.J., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.Dak., Tenn., Tex., Va., Wis.; Mexico. Separating Carex meadii and C. tetanica can be problematic, particularly in the Great Lakes region where they seem to integrade with each other. Carex meadii, the more wide-ranging taxon, can tolerate drier habitats. In addition to the characters in the key, C. meadii tends to be a coarser plant with more grayish green leaves, shorter peduncles (bearing the staminate and proximal pistillate spikes), and thicker spikes. The perigynia, including the proximal ones, are strongly aggregated and borne in more ranks within the spike. Also, the beaks of C. meadii may be more distinct and sharply curved. Due to confusion with Carex meadii, the geographic range of C. tetanica is not fully known.
From Flora of Indiana (1940) by Charles C. Deam
Infrequent in the lake area and in southeastern Indiana; frequent in the dune area. Its habitat is much that of C. tetanica except that C. Meadii also occurs in drier soils and in even more open situations. Carex Meadii as a rule is readily distinct from C. tetanica except at Pine in Lake County where the two species are closely associated and intermediate forms are frequent. The same is true of C. tetanica and C. Garberi, at this station, and, as noted under the latter species, such transitional forms may be due to hybridization.
Much like no. 112 [Carex tetanica Schkuhr ]and perhaps not sharply distinct; lvs 3-7 mm wide; pistillate spikes 10-30 נ5-7 mm, the crowded perigynia in ca 6 rows, obovoid, 3.3-4.2 mm, broadest above the middle and abruptly rounded to the tip, sometimes with a very short, outcurved beak; 2n=52. Dry open prairies and meadows; N.J. to Mich. and Sask., s. to N.C., Ga., Ark., and Tex.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.