Var. fláccida, Bailey. Lower, scarcely exceeding 12–15´ in height; spikes 2–4, all sessile and approximate at the top of the culm, small and straight (1´ long or less), dull brown or reddish-brown, loosely flowered and entirely lacking the dense and comose appearance of the type; perigynium very thin and much inflated, the body usually larger than in the type and more gradually contracted into the beak.—N. Y. to N. J.; apparently scarce.
C. lùrida × lupulìna, Bailey. Very like C. lurida, but the spikes usually all approximate or only the lowest separated, erect or spreading, all sessile, green or greenish, often curved; perigynium very long-beaked and ascending; staminate spike one, sessile or very nearly so, strongly resembling that of C. lupulina. (C. tentaculata, var. altior, Boott.)—Mass., Conn., and N. Y.; little known. C. lupulina × retrorsa is distinguished from this by its yellow or straw-colored more scattered spikes which are shorter and always straight, and the loose, larger and more inflated perigynia.
[*] 1.—[+] 4. Pseudocypèræ.
[++] Spikes all erect or ascending.
17. C. Schweinítzìi, Dewey. Soft but erect, 1–2° high, stoloniferous, yellowish-green and becoming straw-colored in drying; culm flattish and smooth; leaves broad (3–4´´), the radical longer than the culm, the others mostly short; spikes 3–4, the lower one or two short-peduncled, narrowly long-cylindrical (1½–3´ long, 4´´ broad); perigynium thin and somewhat inflated, prominently few-nerved, the long beak short-toothed, ascending; scale awned and commonly rough at the tip, a little shorter than the perigynium.—Swamps, W. New Eng. to N. J., and west to Mich.; local.
[++][++] Spikes widely spreading or drooping.
18. C. hystricìna, Muhl. Slender but erect, 1–2° high; culm very sharply angled and rough, at least above; leaves rather narrow, roughish; spikes 1–3, borne near the top of the culm, the upper one often sessile, the remainder on more or less filiform stalks, short (rarely 1½´ long) and compactly flowered; perigynium greenish, very strongly 15–20-nerved, the very slender beak strongly toothed; scale linear and rough-awned, nearly or quite as long as the perigynium.—Swales, throughout; frequent. Often confounded with n. 16.
Var. Dudlèyi, Bailey. Taller; spikes larger and slimmer (1½–2½´ long), light straw-colored, all secund and widely divaricate or nodding; perigynium stronger toothed; scales usually more prominent.—Swales, Conn. (Wright), Ithaca, N. Y. (Dudley), Wisc. (Lapham).
19. C. Pseùdo-Cypèrus, L. Tall and stout, 2–3° high; culm thick and very sharply triangular, rough throughout; leaves very long, rough-margined; spikes 3–5, all slenderly peduncled and more or less drooping, all somewhat contiguous, long (mostly 2–3´) and narrowly cylindrical, very compactly flowered; perigynium elliptic-lanceolate, more or less 2-edged, many-costate, the beak shorter than the body, with erect short teeth, strongly reflexed; scale very rough-awned, about the length of the perigynium.—Swamps and lake-borders, N. Eng. to Penn., and Mich.; rare. (Eu.)
Var. Americàna, Hochst. Mostly stouter, the leaves broader (about ¼´); spikes thicker and commonly more drooping; perigynium longer, the beak mostly longer than the body and the teeth long and prominently spreading. (C. comosa, Boott.)—Swamps; common.