234 THE AMERICAN MIDLAND NATURALIST 
Bracts with long closed sheaths. 
Perigynia with’ minute beak. 
Rootstocks slender, long-creeping; scales purplish. 
Seales purplish tinged; perigynia obtusely triangular 28. C. tetanica. 
Seales not purplish tinged; perigynia circular in cross-section. 
29. C. Crawet. 
Rootstocks densely caespitose; scales not purplish tinged. 
30. C. Shrivert. 
Perigynia long beaked. 
Perigynia tuberculate-hispid; culms purple at base, not 
fibrillose; spikes alternate flowered. .31. C. assiniboinensis. 
Perigynia smooth; culms brown at base, strongly fibrillose; 
spikes densely flowered...............0 0004 32. C. Sprengelii. 
Bracts sheathless. 
Leaves pubescent; perigynia depressed at apex...... 33. C. abbreviata. 
Leaves glabrous; perigynia not depressed at apex....34. C. Parryana. 
Perigynia with bidentate beak. 
Pistallatespikes (1 em) Womoe es Wa sero erunerr suena 35. C. viridula. 
Pistillate spikes 2.5-10 cm. long. 
Perigynia with thick walls, the nerves thick; leaf-sheaths breaking 
and conspicuously filamentose. 
Leaf-sheaths glabrous; perigynia teeth less than 2 mm. long 
: 36. C. laeviconica 
Leaf-sheaths soft hairy; perigynia teeth 2.5 mm. long or more 
37. C. atherodes. 
Perigynia with thin walls, the nerves slender; leaf-sheats not 
filamentose. 
Perigynia finely nerved; scales rough awned; spikes drooping. 
38. C. hystricina. 
Perigynia coarsely nerved; scales (except lower) not rough 
awned; spikes erect. - 
Perigynia not retrorse; spikes narrowly cylindric. .39. C. rostrata. 
Lower perigynia retrorse; spikes oblong........ 49. C. retrorsa. 
213. Carex stenophylla Wahl. Kongl. Vet. Akad. Nya Handl. 
(II;) 242 342. (1803): 
Leeds, Pleasant Lake. 
214. Carex camporum Mackenzie, Bull. Torr. Bot. Club 
37: 244. (190). 
Leeds, Peninsula of Lake Ibsen, ‘Thorne; Dickey Co 
(Brenckle). 
215. Carex Douglasii Boott; Hook. Fl. Bor. Am. 2: 213 
pl. 214. (1840). 
Leeds, Pleasant Lake; Dickinson (Cl. Waldron). 
216. Carex Sartwellii Dewey, Am. Journ. Sci. 43: 90. (1842). 
Leeds. 
