600 CYPERACE.E. (SEDGE FAMILY.) 



leaves long and narrow, rough on the edges, the lowest sheaths usually becom- 

 ing prominently fibrillose ; 1 or 2 lowest bracts leafy and equalling the culm ; 

 spikes 3-5, variable in size and shape, scattered, the lowest usually more or 

 less peduncled and clavate and the others sessile, erect or spreading, oblong or 

 cylindric (|-2' long and 2-3" broad), all compactly flowered above but often 

 attenuate at base (or rarely alternate-flowered throughout), the upper mostly 

 staminate at top, all greenish-purple or pallid ; perigynium ovate and small, 

 tawny, mostly lightly few-nerved and somewhat granular, the beak very short 

 and commonly entire; scale obtuse to nearly acute, about equalling the peri- 

 gynium or a little shorter. Swales, throughout; abundant and variable. 



Var. angUStata. Stricter; spikes longer and narrower (3-4' long and 

 about 1|" broad), never clavate, more approximate and always erect, the stami- 

 nate portion usually much longer (often 1 -2'), rust-colored; scales narrower 

 and sharper, mostly longer than the perigynium. (C. angustata, Boott, in part.) 

 Same range as the type, but less common. 



Var. decora, Bailey. Usually smaller ; basal sheaths rarely fibrillose ; 

 spikes shorter (seldom over 1' long), sessile or very nearly so, rarely attenuate 

 at base, spreading, the terminal staminate flowers few, rust-colored ; bracts 

 more spreading ; scales very sharp and spreading, longer than the perigynium. 

 (C. aperta, Man.) N. Eng. to Wise. ; rather rare. 



C. srufcTA X FILIFORMIS. Leaves and culms very slender ; spikes short 

 (!' long or less), sessile and compact, the upper 1 or 2 scarcely bracted, pallid ; 

 perigynium small, smooth. Keweeuaw Co., Mich. (FarweU.) Exactly inter- 

 mediate between the two species. 



35. C. aquatilis, Wahl. Large and stout, glaucous, 2 -4 high; culm 

 very obtuse and smooth ; leaves exceedingly long, broader than in the last, the 

 bracts broad and prolonged far beyond the culm ; spikes 3-5, 1-2' long, very 

 compact or the lowest sometimes attenuate below, erect, thick (3" broad or less) ; 

 perigynium round-ovate or broadly elliptic, nerveless, greenish, imbricated; 

 scale obtuse and much shorter and narrower than the perigynium. Swamps 

 and lake-margins, N. Eng. to Minn. ; not common. (Eu.) 



36. C. lenticularis, Michx. Rather slender but erect, pale throughout, 

 1-2 high; culm sharp, usually slightly rough above; leaves very narrow, 

 numerous, much surpassing the culm ; spikes 3 - 6, more or less aggregated or 

 the lowest remote, the terminal androgynous or staminate, mostly sessile, erect ; 

 perigynium ovate, minutely granular, brown-nerved, the tip empty and entire ; 

 scale pale and obtuse, about -J the length of the perigynium. Gravelly borders 

 of ponds and lakes, northern N. Eug. to Minn. ; mostly local. 



= = Spikes widely spreading or drooping. 



37. C. torta, Boott. Slender but erect, l-2- high, in clumps, with ex- 

 ceedingly tough and cord-like roots ; culm rather sharp, smooth or roughish 

 above ; leaves flat and rather soft, those of the culm very short ; spikes 3-5, 

 mostly somewhat approximate or the lower remote, the upper sessile and ascend- 

 ing but the others drooping, long and slender (often 3' long, 2" broad or less) ; 

 perigynium lance-ovate, thin and green, nerveless, the slim upper half empty 

 and more or less tortuous, the beak entire or erose ; scale purple-margined and 

 very obtuse, shorter than the perigynium. Cold banks and swamps, Vt. to 

 N. C. ; infrequent. 



