138 CYPERACEAE 



achenes sliort-stipitate. Mountain meadows: Mont. — 'Colo. — Ariz. — Nev. 

 Mont.—Alp. Jl-S. 



128. C. atrata L. Culms 2-7 dm. hish, sharply triangular, more or less 

 roughened; l(>ave,s all towards culm base, the blades 2-8 mm. wide; spikes 3-7, 

 at least the lowest separate, oblong or obovoid-oblong, 1-3 cm. long, 5-10 mm. 

 wide, clo.sely flowered in many rows; scales brownish black, narrower but mostly 

 longer than the perigynia, the midvein indistinct; perigynia 3-3.5 mm. long, oval; 

 achenes 2 mm. wide, granular-roughened, short-stipitate. Mountain meadows: 

 Greenl. — -Mont. — Wyo. — -Alaska; Eurasia. Alp. — Suhalp. Je-Au. 



129. C. epapillosa Mackenzie. Culms 1.5-6 dm. high, stiff, sharply tri- 

 angular, smooth; leaves all towards base of the culm, the blades 3-8 mm. wide, 

 nearly flat; spikes 3-6, appro.ximate or the lowest a little separate, sessile or 

 short-peduncled, oblong-obovoid, 1-2.5 cm. long, 6-10 mm. wide, closely flowered 

 in many rows; scales lance-ovate, sharp-pointed, brownish black, narrower than> 

 but about equalling or exceeding the perigynia, the midvein more or less prom- 

 inent; perigynia broadly oval or obovate, 3.5-4 mm. long, 1.5-2 mm. wide, ob- 

 scurely nerved, not granular; achenes slender-stipitate. Mountain meadows: 

 Wyo.— Utah— Calif. Mont.— Alp. Je-Au. 



130. C. Mertensii Prescott. Culms 3-10 dm. high, sharply triangular, 

 rough; leaf -blades flat, 4-7 mm. wide; spikes 1-4 cm. long, 7-10 mm. wide, gynae- 

 candrous, the perigynia numerous, appressed-ascending; scales lance-ovate, 

 acute, brown, with light midvein and margins; perigynia tapering at the apex, 

 minutely beaked. Mountains: Alaska— Mont.— Calif. Mont. — Submont. Jl- 

 Au. 



41. AcuTAE Fries. Culms leafy below, aphyllopodic or phyllopodic; term- 

 inal 1-several spikes staminate (rarely gynaecandrovis), linear, the remaining 

 pistillate, linear to cylindric or oblong, closely many-flowered, sessile or ped- 

 uncled. Bracts sheathless (rarely short-sheathing), leafy or squamiform, bi- 

 auriculate and often darkened at the base. Perigynia membranaceous to cori- 

 aceous, piano- or bi-convex, or turgid, elliptic to obovate, puncticulate, margined, 

 beakless or abruptly minutely beaked, the orifice entire to deeply bidentate. 

 Achenes normally lenticular. Style slender, straight, sometimes exserted, its 

 base not enlarged. Stigmas normally 2. 



131. C. concolor R. Br. Culms 1-5 dm. high, smooth; leaf-blades 3-7 

 mm. wide, with revolute margins; terminal spike staminate, linear; lateral spikes 

 1-4, short-oblong to linear-cylindric, 0.5-4 cm. long, 3-5 mm. wide, sessile or 

 short-stalked; scales obtuse or acutish, blackish with lighter midvein; perigynia 

 2.5-3 mm. long, nerveless or nearly so, the orifice entire. C. rigida Good. C. 

 Bigelovii Torr. Arctic-alpine regions: Greenl. — N.H. — -Alta. — -B.C. — ^ Alaska; 

 Eurasia. Alp. 



132. C. scopulorum Holm. Loosely stoloniferous; culms 1-4 dm. high, 

 sharply triangular, smooth; leaf-blades 3-7 mm. wide, with revolute margins; 

 terminal spike androgynous or staminate; lateral spikes 2-3, approximate, erect, 

 sessile or short-stalked, pistillate or androgynous, 1-2.5 cm. long, 6-7 mm. wide; 

 scales obtuse, black, the midvein obsolete; perigynia 2.5-3.5 mm. long, with 

 short but prominent beak, nerveless. Mountains: Mont. — -Colo. — Wash. 

 Mont. — Alp. Jl-Au. 



133. C. chimaphila Holm. Loosely cespitose and stoloniferous; the culms 

 1-4 dm. high, scabrous, flattened, triangular; leaf-blades light green, 3-5 

 mm. wide, with slightly revolute margins; spikes 3-4, the upper approximate 

 and sessile or short-peduncled, the lowest more distant, peduncled, the terminal 

 staminate or androgynous, the lateral pistillate or androgynous, 1-3 cm. long, 

 7-10 mm. wide; scales lanceolate, acute or acuminate, Ijlack, with lighter or 

 obsolete midvein; perigynia 2.5-3.5 mm. long, abruptly minutely beaked. Pos- 

 sibly merely a form of C. scopulorum Holm. Mountain slopes: Mont.^ — -Colo. 

 Alp. — Suhalp. Jl-Au. 



134. C. aperta Boott. Stoloniferous; the culms 5-10 dm. high, sharply 

 triangular, rough above; leaf-blades 2.5-5 mm. wide; terminal spike staminate; 



