179 C. ampullacea Good. Spikes 2 or 3, cyl., erect; spikes 2 or 3, lons-cyl., erect, quite dense, short-ped., bracteate; perig. ovate-globous, a little inflated, diverging, veined, glabrous, abruptly contracted to a small, round, bifurcate beak, a little longer than the lanceolate glume; culm 20 to 30', obtuse-angled, with long lvs. and bracts; light green. - Marshes over the country, not abundant

180 C. monile Tuckm. (E. t. 71.) Spikes 2 to 4, long-cyl., slender, with long-lanceolate gls.; spikes 2 or 1, long-cyl., short-ped., rather loose, tapering below sometimes and more loose, remote, erect, bracteate; perig. globous or ellipsoid, inflated, short-rostrate, bidentate, yellowish, many-veined, more than twice longer than the oblong-lanc. gl.; culm 15 to 30', erect; lvs. and bracts long, bright green. - Marshes, not abundant, N. Eng. to 0. and westward.

181 C. Olneyi Boott (t. 40.) Spikes about 3, cyl., slender, near; spikes

commonly 2, cyl., thick, dense, yellowish, approx. more or less ped., the lowest tapering below, more lax at the base, often some nodding and bracted; perig. inflated-ovoid, with a short, cyl., scabrous, bifurcate beak, diverging, longer than the lane. gl.; culm 15 to 22', stout, obtuse-angled, rough above, shorter than the long, stiff, white-edged lvs. - R. I. (Olney).

182 C. Tuckermani Boott (t. 38). Spikes 2 - 3, cylindric, lower ones sessile and short, with an oblong, acutish glume; spikes 2 - 3, oblong, cyl., thick and large, scarcely pedunculate, subloose-flowered; perig. much inflated, ovate, large, conic, costate, bifurcate, all glabrous, nerved, twice longer than the ovate-lane. gl; culm about 2f, erect, scarcely scabrous; bracts and lvs. long, not wide; light green. - Wet places in meadows, common, and has been ranked under C. bullata. Distinguished from No. 181, by the short, smooth beak of its membranous, pellucid perig. as well as by its different spikes.

183 C. vesicaria L. Spikes about 3, erect, oblong; spikes 2 - 3, cyl., erect, dense-flowered, alternate, long-bracteate; perig. ovate, oblong-conic, terete, inflated, rostrate, nerved, diverging, glabrous, bicuspidate, nearly twice longer than the oblong-lanc. gl; culm about 2f, shorter than the lvs. - Bright green. Marshes. Not common.

184 C. bullata Schk. Spikes 3, erect, slender, cyl., with oblong-lanceolate glumes; spikes 2 - 3, rather oblong, cyl., nearly erect; perig. ovoid-globous, inflated, glabrous, costate, with a long, scabrous beak, bifurcate, longer than the lane. gl.; culm 20 - 30' high, rather slender, triquetrous, scabrous above, leafy and shorter than the leaves. - Glabrous, light green. In wet meadows. Common. This is C. bullata as described in Sill. Jour., Vol. ix. p. 71, and named by Schk. from its (ball-shaped) globous perigynium, comporting with his fig. 166. Carey and others have adopted another form under that name, which hero follows, named from the inflation of the fruit.

185 C. physema Dew. Spikes 2 or 3, cyl., slender, contiguous, the lowest bracteate; spike 1, rarely 2, subrotund or oblong-cyl, thick, dense-flowered, remote, yellowish, the lowest ped., at length nodding, with a bract leafy and surpassing the culm; perig. turgid-ovate, with a long, cyl., scabrous beak, divaricate, inflated, glabrous, broader and longer than the lanceolate, acute, white-edged gl.; culm 12 to 24', slender, firm, shorter than the narrow, flat, firm, light green lvs. - N Eng. to Penn., in humid meadows. (C. bullata Boott, t. 39, nee Schk.)

186 C. oligosperma Michx. Spikes several, sometimes one, erect, slender, long-cyl., with an oblong, obtusish gl.; spikes 1 - 3, ovate, globular, sessile, distant; perig. few, ovate, inflated, acute, nerved, short-rostrate, entire at the orifice, glabrous, a little longer than the ovate-lane. gl.; culm 1 - 2f, scabrous above, leafy below; lvs. involute and rush-like, light green. - Marshes and lake borders, Can., N Eng., N. Y., Mich, and Ga.