142 CYPERACEAE 



exceeding the inflorescence, normally sheathless. Perigynia ascending, spread- 

 ing, or even reflexed, membranaceous, smooth, from little to much inflated, 

 suborbicular in cross-section, coarsely man} -ribbed or nerveless, contracted into 

 a beak, the beak entire to bidentate. Achenes much shorter than the perigynia, 

 triangular or lenticular, continuous with the usually tortuous style. Stigmas 3 

 or 2. 



155. C. miliaris Michx. Culms 3-6 dm. tall, smooth, little filamentose at 

 the base; leaf -blades 2 mm. wide; staminate spikes 1 or 2; pistillate spikes 1-3, 

 oblong-cylindric, 8-25 mm. long, 5-7 mm. wide; perigynia at most faintly nerved, 

 2-3 mm. long, exceeding the scale. Border of lakes and streams: Lab. Me. 

 B.C. Boreal. Jl-Au. 



156. C. saxatilis L. Culms 3-8 dm. tall, more or less roughened; leaf-blades 

 1.5-3.5 mm. wide; staminate spikes 1 or 2; pistillate spikes 1 or 2, separate, oblong- 

 cylindric, 1.5-3.5 cm. long, 6-8 mm. wide, closely 25-75-flowered; scales ovate- 

 lanceolate, sharp-pointed, brownish with lighter midvein, hyaline at the apex; 

 perigynia obscurely nerved, 4.5-5 mm. long, 1.75-2.25 mm. wide, exceeding the 

 scales, minutely beaked. C. physocarpa Presl. Arctic and subarctic places: 

 Colo. Mack. Alaska; Eurasia. Alp. Mont. Je-Au. 



157. C. oligosperma Michx. Long-stoloniferous; culms slender, 4.5-9 dm. 

 high, exceeding the leaves; leaf-blades 3 mm. wide, involute in age; staminate 

 spike stalked, linear; pistillate spikes 1-2, subglobose or short-oblong, mostly 

 5-15-flowered; scales acute or slightly mucronate, much shorter than the peri- 

 gynia; perigynia ovoid, inflated, strongly few-nerved, yellowish green, shining, 

 5 in.n. long, 3 mm. in diameter, the beak minutely bidentate. In bogs: Lab. 

 Pa. Ind. Sask. Je-S. 



158. C. Raeana Boott. Culms 3-6 dm. high, very slender, triangular and 

 roughened above, reddened at the base; leaf -blades flat, 2 mm. wide, little nodu- 

 lose; staminate spikes I or 2; pistillate spikes 1-3, narrowly cylindric, 1.5-5 cm. 

 long, 5 mm. wide, short-peduncled ; scales lanceolate, acuminate; perigynia 5-6 

 mm. long, closely enveloping the achene, yellowish green, strongly few-nerved. 

 (Probably a form of the next.) Lake and river shores: Me. Que. Sask. 

 Boreal. Je-Au. 



159. C. vesicaria L. Culms 3-9 dm. high, acutely angled and rough above; 

 leaf-blades 3-6 mm. wide; staminate spikes 2-4; pistillate spikes 1-3, sessile or 

 short-peduncled, erect, oblong-cylindric, 2.5-7 cm. long, 6-15 mm. wide, many- 

 flowered; scales ovate or lanceolate, acute, acuminate, or short-awned; perigynia 

 5-8 mm. long, yellowish green, 8-10-nerved. C. monile Tuckerm. Wet mead- 

 ows and swamps: Que. Pa. Ohio Calif. B.C.; Eurasia. Plain. Je-Au. 



160. C. exsiccata Bailey. Culms 3-10 dm. high, acutely triangular and 

 rough above; leaf-blades 3-*6 mm. wide; staminate spikes 2-4', pistillate spikes 

 1-3, sessile or short-peduncled, erect, cylindric, 2-7 cm. long, 10-14 mm. wide, 

 closely many-flowered; scales ovate, sharp-pointed; perigynia 7-9 mm. long, 

 lanceolate, tapering into the beak, yellowish green, 8-10-nerved. "C. mirata 

 Dewey" Holm. Wet places: Alaska Mont. Calif. Submont. Je-Au. 



161. C. rostrata Stokes. Culms stout, 3-12 dm. high; leaf-blades 2-12 mm. 

 wide; staminate spikes 2-4; pistillate spikes 2-4, erect, cylindric, densely flowered, 

 sessile or short-peduncled, 5-15 cm. long, 6-20 mm. wide; scales lanceolate, 

 awned or acute; perigynia ovoid, spreading at maturity, few-nerved, 4-8 mm. 

 long, abruptly beaked. C. utriculata Boott. Boggy places: Lab. Del. N.M. 

 Calif. B.C. Alaska; Eurasia. Plain Mont. Je-S. 



162. C. retrorsa Schw. Culms stout, 3-10 dm. high, smooth or slightly 

 roughened above; leaf-blades 5-^10 mm. wide; staminate spikes 1-3; pistillate 

 spikes 3-8, contiguous and sessile or nearly so, or the lower distant and long- 

 stalked, cylindric, densely many-flowered, 2.5-7.5 mm. long, 14-20 mm. wide; 

 scales lanceolate, acute or acuminate; perigynia ovoid, few-nerved, 7-10 mm. long, 

 tapering into the beak. "C. lupulina Muhl. " of Fl. Colo. Swamps and wet 

 places: Newf. Pa. la. Colo. Wash. B.C. Plain Submont. Jl-O. 



