288 



CYPERACEAE 



Beak of perigynium entire or emarginate, not hispidulous between teeth; scales not rough awned. 



Lower culm sheaths (of the year's growth; strongly yellowish-brown tinged, sharply keeied; 



culms stout; leaf-blades 6-12 mm. wide. 146. C. schottii. 



Lower culm sheaths (of the year's growth) purplish-tinged, not sharply keeled; culms more slender; 

 leaf-blades narrower. 147. C. senta. 



Some or all of the flowering culms arising laterally and not enveloped at base by previous year's tuft of 

 leaves; lower sheaths filamentose. 

 Cespitose or with short ascending stolons; lowest bract from very short to about length of inflorescence; 

 foliage light green; lower sheaths strongly filamentose, smooth or nearly so dorsally. 

 Perigynia plano-convex, broadly ovate to oblong-lanceolate, 3-4 mm. long. 148. C. vudata 



Perigynia unequalling bi-convex, ovoid-orbicular, scarcely 2.5 mm. long. 149. C. suborbiculata. 



Loosely cespitose with long slender horizontal stolons; lowest bract exceeding inflorescence; foliage deep- 

 green; lower sheaths little filamentose, hispidulous dorsally. 

 Perigynia sub-orbicular or broadly obovate. 150. C. eiifycarpa. 



Perigynia oblanceolate or narrowly obovate. 151. C. oxycarpa. 



26. Crvptocarpae. 



Perigynia dull, straw-color or light-brown, slightly granular; lower sheaths of sterile shoot not filamentose. 



152. C lyngbyei. 

 Perigynia shining, brown, smooth; lower sheaths of sterile shoots strongly filamentose. 



153. C. obnupta. 



37. HlRT.^E. 

 Perigynia hairy, the teeth 1.5 mm. long or less. 



Beak of perigynium obliquely cut, shallowly bidentate at maturity; foliage pubescent; staminate scales 



long ciliate. lS4. C. yoscmitana. 



Beak of perigynium deeply bidentate; staminate scales at most erose. 

 Foliage not pubescent; teeth of perigynium beak short. 



Lowest bract strongly sheathing; fertile culms phyllopodic with many leaves, the sheaths not 



breaking and becoming filamentose. 155. C. oregonensis. 



Lowest bract not sheathing; fertile culms aphyllopodic with few leaves, the sheaths lireaking and 

 becoming filamentose. 156. C. lanuginosa. 



Leaf-blades flat, more than 2 mm. wide. 



Leaf-blades involute, 2 mm. wide or less. 157. C. lasiocarpa. 



Sheaths and under surface of leaf-blades hairy; teeth of perigynium beak conspicuous. 



158. C. sheldonii. 

 Perigynia glabrous, the teeth 1.5 mm. long or more; sheaths and leaf-blades hairy. 159. C. atherodes. 



Represented by one species in our range. 



Represented by one species in our range. 



38. EXTENSAE. 



39. Pauciflorae. 



40. Physocarpae. 



160. C. riridiila. 



161. C. pa II ci flora. 



Lower perigynia not reflexed ; bracts moderately exceeding the spikes. 



Perigynia ascending; lower sheaths more or less strongly filamentose; rootstocks short-creeping with short 

 ascending stolons; leaves sparingly nodulose. 

 Perigynia 6-8 mm. long, contracted into the beak. 162. C. vesicaiia. 

 Perigynia 8-10 mm. long, tapering into the beak. _ 163. C. exsiccata. 

 Perigynia spreading at maturity; lower sheaths not filanientose; densely cespitose, sending out long hori- 

 zontal stolons; leaves strongly nodulose. 154. C. rostrata. 

 Lower perigynia reflexed; bracts many times exceeding the spikes. 165. C. retvoisa. 



41. Pseudo-cypereae. 



Perigynia suborbicular in cross-section, more or less inflated; teeth of perigynium beak erect, 0.5-1 mm. long. 



166. C. Iiystrlcina. 

 Perigynia obtusely triangular, scarcely inflated, closely envelophig the achene; teeth of perigynium beak 

 1.5-2 mm. long, recurved or spreading. * 167. C. coinosa. 



1. Carex hepbtirnii Boott. 

 Hepburn's Sedge 



Fig. 677. 



Carex hepburnii Boott in Hook. Fl. Bor. Am. 2: 209. pi. 207. 1840. 

 Carex nardina hepburnii (Boott) Kukenth. in Engler Pflanzenreich 

 4=": 70. 1909. 



Very densely cespitose, the culms 2-15 cm. high. Leaf- 

 blades filiform ; sheaths strongly hyaline-margined above, 

 abruptly contracted into the blades; spike solitary, bract- 

 less, linear-oblong, 5-12 mm. long, androgynous, densely 

 flowered with 1-10 perigynia ; scales ovate, acutish, the 

 midvein conspicuous ; perigynia 3 mm. long, ascending, 

 biconvex, elliptic-ovate, not inflated, the walls thin, gla- 

 brous, striate, stipitate, the beak hyaline tipped, in age 

 bidentulate, obliquely cut and with a closed suture dorsally; 

 achenes usually triangular, or sometimes lenticular; stig- 

 mas 3 or sometimes 2. 



Dry alpine slopes, Hudsonian and Arctic-Alpine Zones; Alberta 

 and Colorado to British Columbia and Washington. Type locality: 

 Rocky Mountains. 



