C YPERA CEA . 1 99 



Terminal spike staminate below, pistillate above (rarely all staminate in No. 47) ; stigmas 



3. ATRATAE. 



Scales shorter than or equalling the perigynia; arctic and alpine species. 

 Orifice of the perigynium minutely 2-toothed ; scales obtuse or acutish. 

 Pistillate spikes 4-10 mm. long, erect. 44. C. alptna. 



Pistillate spikes 8-25 mm. long, drooping when old. 45. C. atratiformis. 

 Orifice of the perigynium entire ; scales acute or awned. 



Perigynium ovate, the style usually protruding. 46. C. stylosa. 



Perigynium obovate, the style not protruding. 47. C, Parryana. 



Scales manifestly longer than the perigynia; bog species. 48. C. Buxbaumii. 



Terminal spike staminate throughout (occasionally pistillate at the top in No. 53); 



stigmas 2, rarely 3 in No. 55. RIGIDAE. 



Lower sheaths becoming very fibrillose ; tufted bog species. 49. C. stricta. 

 Lower sheaths not at all fibrillose, or slightly so. 



Scales shorter than or equalling the perigynia (or longer in No. 50). 

 Culms 0.3-0.6 m. tall; scales acute or acuminate. 



Pistillate spikes linear-cylindric. 50. C. Haydeni. 



Pistillate spikes oblong-cylindric. 51. C. Nebraskensis. 



Culms 0.2-1. i m. tall ; scales obtuse or the lower acute. 

 Scales green. 



Leaves 4-6 mm. wide; pistillate spikes 4-6 mm. thick; perigynia 



nerveless. 52. C. aquatilis. 



Leaves 2 mm. wide ; pistillate spikes 2-4 mm. thick ; perigynia 



faintly few-nerved. 53. C. lenticularis. 



Scales purple or brown. 



Scales shorter than the perigynia ; marsh and meadow species. 



54. C. Goodenovii. 

 Scales equalling or longer than the perigynia; arctic and alpine 



species, 55. C. Bigelovii. 



Culms only 2-17 cm. tall; arctic species. 56. C. subspathacea. 



Scales distinctly longer than the perigynia; northern salt marsh species. 

 Basal leaves 2 mm. wide or less ; scales little longer than the perigynia, 



57. C. sah'na. 

 Basal leaves 2-6 mm. wide ; scales much longer than the perigynia. 



58. C. cuspidata. 



44. Carex alpina Sw. ALPINE SEDGE. (I. F. f. 714.) Culms slender, 

 rough above, leafy below the middle, 1.55 ^m. tall. Leaves roughish, 1-3 mm. 

 wide, shorter than or equalling the culm; spikes 2-4. clustered, the terminal I or 

 2 staminate below, oblong or globose, 4-10 mm. long, sessile, or the lower pedun- 

 cled; perigynia oval, orbicular or obovoid, light green, about 2 mm. long, tipped 

 with a very short and minutely 2-toothed beak, nerveless or with a few faint 

 nerves, equalling or slightly shorter than the ovate black or purple-brown scales. 

 In rocky places, Quebec to James' Bay and Athabasca, western Ont. and Isle 

 Royale, Lake Superior, south in the Rocky Mts. to Colo. Also in Europe. 

 Summer. 



45. Carex atratiformis Britton. BLACK SEDGE. (I. F. f. 715.) Glabrous; 

 culms slender, sharp-angled, rough above, 2-5 dm. tall, usually leafy only below. 

 Leaves 2-4 mm. wide, rarely over 1.5 dm. long, much shorter than the culm; spikes 

 2-5, dense, oblong-cylindric, 8-25 mm. long, about 5 mm. in diameter, the terminal 

 one usually staminate at the base and sessile, or nearly so, the others slendtr- 

 stalked; lower bracts 1-3.5 cm - l n g Ver 7 narrow, the upper subulate; perigynia 

 flattened, ovate or nearly orbicular, puncticulate, about 2 mm. long, tipped with a 

 short, 2-toothed beak; scales black or reddish-brown, oblong, slightly narrower 

 than the perigynia and about equalling them. Newf. to the mountains of N. E., 

 west to the N. W. Terr. Summer. 



46. Carex stylosa C. A. Meyer. VARIEGATED SEDGE. (I. F. f. 716.) 

 Culms slender, 3-4 dm. tall, rough and leafless above. Leaves 3 mm. wide; 

 staminate spike solitary, nearly sessile, often pistillate for one-half its length or 

 more; pistillate spikes 2 or 3, oblong-cylindric, erect, 8-12 mm. long, about 3 mm. 

 in diameter, the lower slender-stalked and subtended by a subulate bract; peri- 

 gynia ovate, slightly inflated, brown, minutely granulate, less than 2 mm. long, 

 nerveless, beakless, the orifice entire and closed by the usually protruding style; 

 scales black with white veins, obtusish, shorter than the perigynia. Lab. and 

 Greenland to Alaska. Summer. 



