54. C. æstivàlis, M. A. Curtis. Slender but erect, 1–1½° high; leaves very narrow, flat, shorter than the culm, the sheaths pubescent; spikes 3–4, erect or spreading, 1–2´ long and very loosely flowered, all but the lowest short-stalked; perigynium very small, ovate, scarcely pointed and the orifice entire, few-nerved, about twice longer than the obtuse scale.—Saddle Mountain, W. Mass., and southward in the mountains to N. C.; rare.
55. C. gracíllima, Schwein. Tall and slender, sometimes diffuse, 1½–3° high; leaves broad and flat (the radical about 3´´ wide), very dark and bright green; spikes 3–4, scattered, the terminal rarely staminate, densely flowered except at base, peduncled and drooping, green; perigynium ovate, thin and slightly swollen, nerved, obtuse, orifice entire, twice longer than the very obtuse scale.—Woodlands and low meadows, throughout; common.—In poorer soil and sunny places, it runs into var. hùmilis, Bailey, and is then smaller, has much narrower leaves and very small erect spikes (2–12-flowered), and mostly smaller perigynia.
C. gracíllima × hirsùta, Bailey. In habit like var. humilis; spikes tawny; perigynium like that of C. triceps, var. hirsuta; plant smooth, or very minutely pubescent under a strong lens.—Philipstown, N. Y. (Barratt).
C. gracíllima × pubéscens, Bailey. Tall and erect; leaves narrower than in the last, usually slightly hairy; spikes slender, erect or slightly spreading, often staminate at top; perigynium exactly intermediate between the two species, ovate, obscurely nerved, sparsely hairy, beaked, about the length of the ovate ciliate rough-awned scale. (C. Sullivantii, Boott.)—Columbus, Ohio (Sullivant); Yonkers, N. Y. (E. C. Howe); Stanton, Del. (Commons).
[++][++] Perigynium large, prominently inflated.
56. C. formòsa, Dewey. Slender, erect, 1–2½° high; leaves flat, mostly rather broad, those of the culm very short; spikes 3–5, scattered, oblong or short-cylindrical (1´ long or less), compact, all flexuose or drooping; perigynium ovate, puncticulate, obscurely nerved, short-beaked with a slightly notched orifice, all but the lowest one or two twice longer than the blunt or cuspidate scale.—Woods and copses, Vt. to Mich.; local.
57. C. Davísii, Schwein. & Torr. Always taller; spikes heavier; perigynium more inflated, strongly nerved and prominently toothed, no longer or shorter than the conspicuously awned and spreading scale.—Wet meadows, W. Mass. to S. Minn., and southward; rare east and northward.
[*] 4.—[+] 6. Gríseæ.
58. C. grísea, Wahl. Stout, 1–2° high; leaves broad (2–3´´) and slightly glaucous; bracts broad and leaf-like, diverging, very much exceeding the culm; staminate spike small and sessile; pistillate spikes 3–4, short (1´ long or less), the highest two usually contiguous to the staminate spike and sessile, the others somewhat remote and peduncled, all erect, compact; perigynium oblong, pointless, marked with impressed nerves, turgid and cylindric, all but the lowest longer than the narrow, cuspidate or blunt, nerved scale.—Moist grounds, throughout, except along our northern borders; common.—Var. angustifòlia, Boott. Much more slender; leaves scarcely half so wide, the bracts, especially, much narrower and shorter and more erect; spikes slender, perigynium scarcely inflated, triangular-oblong, bearing a sharp beak-like point, 2-ranked; scale nerveless, long-awned and spreading. N. J. to S. Ohio, and southward; common.—Var. globòsa, Bailey. Low, 3–12´ high, often spreading; spikes few-flowered, often with but 2 or 3 perigynia; perigynium short, inflated, very blunt, nearly globose or obovate; scale short, not prominently cuspidate or the upper ones wholly blunt. Mo., Kan., and southward.
Var. (?) rígida, Bailey. Rigid; leaves rather narrow, long and erect; staminate spike prominently peduncled; pistillate spikes scattered, all more or less stalked, conspicuously 2 ranked; perigynium triangular-oblong, hard, longer than the cuspidate ascending scale.—Sellersville, Penn., and Del.