[++][++] Spikes much larger, cylindrical.
[=] Scales all, or all but the very lowest, smooth.
11. C. utriculàta, Boott. Very stout and robust, 3–4° high; leaves broad (4–6´´) and flat, very prominently nodulose, particularly below; spikes 3–4, 3–6´ long, very thick and dense above but usually more or less attenuate below, erect or nearly so, all but the lowest sessile or very short-stalked; perigynium ovate, only moderately inflated, rather abruptly contracted into a short toothed beak, at maturity usually squarrose, rather prominently few-nerved, the upper longer than the sharp scale, the lower shorter than or only equalling the sharper or awned scale. (C. rostrata, Bailey, etc.)—Swamps, everywhere; common. Passes imperceptibly into var. mìnor, Boott, which is distinguished by its much smaller size, spikes 2½´ long or less, smaller perigynium, blunt scales, and narrower and little nodulose leaves. With the type.
12. C. monìle, Tuckerm. Rather slender but erect, 2–3° high, the culm sharply angled and usually rough above; pistillate spikes 2–3, the lowest one or two short-stalked, erect or spreading, 1–3´ long, narrowly cylindrical; perigynium turgid, prominently beaked, about 10-nerved, ascending, longer than the very sharp scale. (C. Vaseyi, Dewey.)—Meadows and swales; common.—In var. monstròsa, Bailey, the plant is very slender throughout, and the terminal spike more or less pistillate, while the remaining spikes are reduced to one or two which are very small and loosely flowered and usually on very long filiform peduncles. E. Mass. (Swan).
13. C. Tuckermàni, Dewey. Differs from the last chiefly in the comparatively shorter (1–2´ long) spikes, which are much thicker (usually ½´ or more); perigynium greatly inflated and very thin and papery, the body broader than long (about 3´´ thick); scale thin and narrow, acute, all but the very lowest less than half the length of the perigynium.—Swamps, W. New Eng. to N. J., and west to Minn.; frequent.
14. C. bullàta, Schkuhr. (Pl. 6, fig. 15–20.) Slender, 1–2° high; culm very sharply and roughly angled, thin but stiff; leaves narrow, rough-edged, stiff; spikes 1 or 2, remote, short and thick (rarely 1½´ long), sessile or the lower short-peduncled, more or less spreading; perigynium turgid but very firm, dull straw colored and shining as if varnished, prominently few-nerved, the long beak usually minutely roughened; scale membranaceous and blunt, about {1/3} as long as the perigynium.—Swamps from E. Mass, to N. J. and E. Penn., and southward; frequent.
C. bullàta × utriculàta, Bailey. Perigynium considerably smaller and more spreading, less shining; scales longer and sharper. (C. Olneyi, Boott.)—Providence, R. I. (Olney).
15. C. retrórsa, Schwein. Stout, 2–3° high; culm obtusely angled and smooth or nearly so; leaves broad and soft, roughish, much longer than the culm; spikes 3–5, approximate near the top of the culm or the lowest remote, all but the lowest 1 or 2 sessile, 1–2´ long and very compactly flowered, erect or spreading; perigynium very thin and papery, much inflated, prominently nerved, strongly reflexed; scale very short and small.—Swamps, from Penn. northward; common.—In var. Hárth, Gray, a common monstrous form, the spikes are more or less scattered and peduncled, loosely flowered, and the perigynium less reflexed or spreading.
[=][=] Scales all rough-awned.
16. C. lùrida, Wahl. Variable in size, mostly ranging from 1½–3° high, stout; culm rather obtusely angled and smooth; leaves long and loose, rough; spikes 2–4, variously disposed, the 1 or 2 upper sessile, nearly erect or often drooping, very densely flowered; perigynium thin and turgid, often somewhat shining, rather lightly about 10-nerved, very long and slenderly beaked, ascending; staminate spike single, scales linear, half as long as the perigynium or more. (C. tentaculata, Muhl.)—Swamps, N. Eng. to S. Ill., and southward; abundant eastward. Very variable.—Var. grácilis, Bailey. Plant more slender; spikes 2–3, very small and narrowly cylindrical (1´ long or less, and 3´´ broad or less). Mts. of Vt., Penn., and Tenn.