[++] Perigynium ovate-lanceolate, with winged margins.
125. C. siccàta, Dewey. Extensively creeping, 1–2° high, erect; leaves firm, narrow, about the length of the culm; staminate flowers variously situated, usually some of the spikes wholly sterile; spikes 3–5, aggregated or separated, ovoid or short-oblong, silvery-brown; perigynium firm, nerved on both faces, the long beak rough and toothed, the margins prominent or sometimes very narrow; scale acute, about the length of the perigynium.—Sandy fields and banks, N. Eng. to Ohio, west and northward; frequent.
[++][++] Perigynium ovate-lanceolate or narrower, scale-like, with little distinction between body and margin.
126. C. Muskinguménsis, Schwein. Robust, erect, 2–3° high; leaves many and lax, loosely sheathing, those on the sterile shoots crowded near the top, all flat and long-pointed; spikes 6–12, contiguous, erect, narrowly cylindric (often 1´ long), becoming light brown and presenting a dried appearance, very densely flowered; perigynium linear-lanceolate (3´´ long), prominently nerved, ciliate on the white margins above, appressed, twice the length of the scale or more. (C. arida, Schwein. & Torr.)—Woods and copses, Mich. and Ohio to Ill. and Wisc.; local.
127. C. tribuloìdes, Wahl. Stout and erect, 2–3° high; leaves narrower than in the last, loosely sheathing; spikes 6–15, aggregated into an oblong or somewhat interrupted heavy head, short-oblong or sometimes nearly globular, green or tawny-green, compact, not narrowed above; perigynium linear-lanceolate (3´´ long), obscurely nerved, erect but the points conspicuous, rough-margined, nearly twice the length of the scale. (C. lagopodioides, Schkuhr.)—Open swales; frequent.—Var. turbàta, Bailey. Culm softer and often lax; the leaves broader; spikes more loosely disposed, forming a head 1–2´ long, which is slender and more or less interrupted but always erect, green, becoming tawny, if at all, only when the perigynia begin to fall, obovate-oblong (¼ to rarely ½´ long), contracted below; perigynium ascending and more appressed, the points therefore not conspicuous. Woods, throughout; rare.—Var. redúcta, Bailey. Very slender, 1–2° high, the culm projecting beyond the leaves; spikes 2–10, small and nearly globular (usually less than 3´´ broad), all usually distinct, the lowest separated, brown, especially at maturity, the head often flexuose; perigynium small, the points spreading and conspicuous. Copses, N. Eng. to Dak.; infrequent.
Var. Bébbii, Bailey. Stiff or rather slender, erect, 1–2½° high; head dense, ovoid or oblong (¼–¾´ or very seldom 1´ long), the lowest spike only rarely distinct, straw-colored; spikes small (3´´ long or less), their axes ascending; bracts at the base of the head small or none; points of the small perigynium conspicuous. (C. Bebbii, Olney.)—Dry low grounds, throughout; common.
Var. cristàta, Bailey. Stout and stiff, 1½–3° high; head more or less open or at least the lower 1 or 2 spikes commonly distinct, 1´ long or more, green; spikes larger than in the last and almost exactly globular, their axes more divergent or fully horizontal; bracts usually conspicuous, sometimes one of them foliaceous; perigynium spreading, the points more conspicuous. (C. cristata, Schwein.)—Moist ground, throughout from Penn. northward; common.
128. C. scopària, Schkuhr. Rather slender but erect, 1–2½° high; leaves very narrow, shorter than the culm; head short and comparatively thick, always tawny or brown, bractless or nearly so; spikes 3–8, all contiguous or bunched, ovate-oblong, always prominently narrowed or cone-shaped above, ascending; perigynium as in n. 127, but erect or ascending.—Open swales, throughout; common eastward.
Var. mìnor, Boott. Much smaller, 6–10´ high, the leaves very narrow; head very small and darker brown; spikes very small (2–4´´ long).—Rocky and sterile places, northward; frequent.
[++][++][++] Perigynium ovate or broader, thickened in the middle, wing-margined (in n. 129 marginless).