596 CTPERACE^. (sedge FAMILY.) 



.w ++ Spikes widely spreading or drooping. 



18. C. hystricina, Muhl. Slender but erect, 1-2° high; calm very 

 sharply augled and rough, at least above ; leaves rather narrow, roughish ; 

 spikes 1-3, borne near the tup of the culm, the upper one often sessile, the 

 remainder on more or less filiform stalks, short (rarely 1^' long) and com- 

 pactly flowered; perigynium greenish, very strongly 15-20-nerved, the very- 

 slender beak strongly toothed ; scale linear and rough-aAvned, nearly or quite 

 as long as the perigynium. — Swales, throughout ; frequent. Often confounded 

 with n. 16. 



Var. Dudldyi, Bailey. Taller ; spikes larger and slimmer (1|- 2^' long), 

 light straw-colored, all secund and widely divaricate or nodding ; perigynium 

 stronger toothed; scales usually more prominent. — Swales, Conn. ( Wright), 

 Ithaca, N. Y. (Dudlei/), Wise. (Lapham). 



19. C. Pseudo-Cyperus, L. Tall and stout, 2 - 3° high ; culm thick 

 and very sharply triangular, rough throughout ; leaves very long, rough-mar- 

 gined; spikes 3-5, all slenderly peduncled and more or less drooping, all 

 somewhat contiguous, long (mostly 2-3') and narrowly cylindrical, very com- 

 pactly flowered ; perigynium elliptic-lanceolate, more or less 2-edged, many- 

 costate, the beak shorter than the body, Avith erect short teeth, strongly reflexed ; 

 scale very rough-awned, about the length of the perigynium. — Swamps and 

 lake-borders, N. Eng. to Peun., and Mich. ; rare. (Eu.) 



Var. Americana, Hochst. Mostly stouter, the leaves broader (about ^') ; 

 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. 



* 1. — -t- 5. Squarrbsce. 



20. C. Sten61epis, Torr. Stout and very leafy, 1-2° high ; culm ob- 

 tusely angled, very smooth ; leaves about 3" broad, rough on the nerves, the 

 upper and the bracts very much longer than the culm ; terminal spike often 

 pistillate at top ; other spikes 3-5, the uppermost sessile on the zigzag rha- 

 chis, short (1 - H' or less) and evenly cylindrical, often staminate at top ; peri- 

 gvnium very abruptly contracted into a short but slender toothed beak, shorter 

 than the long-linear and rough scale. — Swamps and meadows, central Penn., 

 to X. Ohio, Avest and southward ; frequent. 



21. C. squarrosa, L. Cespitose, 2 - 3° high ; culm sharply angled, more 

 or less rough above ; leaves broad and weak, roughish, exceeding the culm ; 

 bracts much less prominent than in the last; spikes 1-3, thick, the terminal 

 alwavs two thirds pistillate or more, the remainder more or less stalked, erect 

 or slightly nodding, globular or oblong-cylindric, brown, exceedingly densely 

 flowered ; perigynium larger, the beak rough ; scale short and usually invis- 

 ible. — Bogs, throughout ; infrequent. 



* 2. Trachychl^n^. — -t- 1. Shortiancs. 



22. C. Shorti^na, Dewey. Tall and slender but strict, in small clumps, 

 2-3° high; leaves about |' broad, flat, rough on the nerves; spikes 3-5, 

 somewhat approximate near the top of the culm, the lowest 2 or 3 short-pe- 

 duncled, erect, small (1' long or less, and 2" wide), evenly cylindrical, exceed- 

 ingly densely flowered ; perigynium small, circular or round-ovate, flat, 



