Var. alpícola, Wahl. Low and stiff, or at lower altitudes becoming somewhat slender, seldom much over 1° in height; spikes small, globular or nearly so, dense, well defined and brown or tawny; perigynium as in the type, ascending. (C. vitilis, Fries.)—Mountains from N. Eng. to Ga., sparingly along our northern boundary, and far westward. (Eu.)
Var. polystàchya, Boott. Erect and mostly strict, not glaucous, 1½–2½° high, scarcely tufted; leaves very lax and exceeding the culm; spikes oblong, more or less aggregated in an oblong interrupted head, the lowest 1 or 2 subtended by short scale-like bracts; perigynium somewhat spreading. (C. arcta, Boott.) Low woods, N. New Eng. to N. Minn.; rare. Resembles C. echinata, var. cephalantha.
120. C. Norvégica, Willd. Low and stiff, but rather slender, 1° high or less; leaves very narrow, mostly shorter than the culm; spikes 3–5, somewhat scattered, brown, globular or oblong, compactly many-flowered, the terminal one long-contracted below with the staminate flowers; perigynium very short-ovate, thick, the beak rough, a little longer than the very obtuse scale.—Salt marshes, Maine, and northward, rare. (Eu.)
121. C. tenuiflòra, Wahl. Very slender and diffuse, 1–1½° high, in tufts; leaves very narrow and lax, shorter than the filiform culm; spikes 2–4, all loosely few-flowered and silvery-green, and aggregated into a small globular head; perigynium elliptic, obscurely nerved, smooth, beakless, spreading, about the length of the white thin scale.—Bogs, N. New Eng. to N. Minn.; local. (Eu.)
b. Bracts much prolonged, the lowest 2–3´ long.
122. C. trispérma, Dewey. (Pl. 6, fig. 1–5.) Exceedingly slender, in small and loose tufts, the weak reclining culms 1–2° long; leaves soft and narrow, shorter than the culm; spikes 2–3, 1–3´ apart, silvery-green, 2–3-flowered; perigynium very thin, finely nerved, the beak entire or nearly so; scale acute, very thin, usually shorter than the perigynium.—Cold bogs, throughout; common northward.
[=][=] Perigynium ovate-lanceolate to linear-lanceolate.
123. C. Deweyàna, Schwein. Weak, 1–1½° high; leaves flat and soft, shorter than the culm, yellowish-green; spikes 3–6, mostly oblong or sometimes but 2–3-flowered, loose, the upper ones contiguous but the lower 1 or 2 usually considerably separated on the zigzag rhachis and mostly subtended by a bract, all silvery-green; perigynium ovate-lanceolate or narrower, very thin in texture, nerveless, somewhat thickened below on the outer face, the long beak rough; scale very thin, acute or cuspidate, about the length of the perigynium.—Dry woods; common.
124. C. bromoìdes, Schkuhr. Lax, 1–2° high, in dense stools; leaves very narrow, about as long as the culm; staminate flowers variously situated in the head, sometimes a few spikes wholly sterile, rarely the plants diœcious; spikes 3–6, oblong or short-cylindric, erect, silvery-tawny or brown; perigynium linear-lanceolate, firm especially at the base, prominently nerved, the long and roughened beak toothed; scale sharp, shorter than the perigynium.—Open bogs; common.
[*] 12.—[+] 2. Ovàles.