SEDGE FAMILY 119 



Perigynia densely or strongly pubescent. 



Nerves of the perigynia obscured by pubescence, the teeth of beak short. 

 Leaf-blades flat, more than 2 mm. Avide. 143. C. lanuginosa. 



Leaf-blades involute, 2 mm. wide or less. 144. C. lasiocarpa. 



Nerves of the perigynia prominent, the teeth of beak prominent, slender. 



145. C. Houghtonii. 

 of the perigynia including teeth nearly as long as body, the teeth 1.5 mm. long or 



more. 

 Perigynia glabrous. 



Perigynia ovoid, the teeth less than 2 mm. long, erect or spreading; scales acute 



to aristate; leaf-blades glabrous. 146. C. laeviconica. 



Perigynia lanceolate or ovoid-lanceolate, the teeth 2-4 mm. long, widely spread- 

 ing; scales long-aristate ; leaf-blades pubescent beneath. 



147. C. atfierodes 

 Perigynia hairy. 148. C. Sheldonii. 



43. EXTENSAE. 



Perigynia 2-3 mm. long, the beak scarcely half as long as the body. 



149. C. viridula. 

 Perigynia 4-6 mm. long, the beak about as long as the body. 150. C. flava. 



44. PAUCIFLORAE. 

 Rhacheola present, conspicuously exserted; culms with many leaves. 



151. C. microglochin. 

 Rhacheola absent or rudimentary, not conspicuously exserted; culms with few leaves. 



152. C. pattciflora. 

 45. PSEUDO-CYPEREAE. 



Perigynia suborbicular in cross-section, more or less inflated. 153. C. hystricina. 

 Perigynia obtusely triangular, scarcely inflated, closely enveloping achene. 



154. C. comosa. 

 46. PHYSOCARPAE. 



Perigynia scarcely inflated; beak entire or emarginate; stigmas normally two and achenes 



lenticular. 

 Perigynia lanceolate; fertile culms fllamentose at the base; rootstocks creeping. 



155. C. miliaris. 

 Perigynia ovoid; fertile culms rarely if ever fllamentose at the base; plant loosely 



stoloniferous. 156. C. saxatilis. 



Perigynia from little to much inflated; beak bidentate; stigmas normally three and 



achenes triangular. 



Pistillate spikes globose or short-oblong, 5-15-flowered. 157. C. oligosperma. 

 Pistillate spikes oblong to cylindric, 15-many-flowered. 



Lower perigynia not reflexed; bracts moderately exceeding the spikes. 



Parigynia ascending; lower sheaths more or less strongly fllamentose; culms 



sharply triangular. 

 Perigynia 6-8 mm. long. 



Perigynia oblong-ovoid, tapering into the beak; spikes loosely flowered 



at base. 158. C. Raeana. 



Perigynia ovoid or globose-ovoid, contracted into the beak; spikes more 



closely flowered. 159. C. vesicaria. 



Perigynia 8-10 mm. long, tapering into the beak. 160. C. exsiccata. 

 Perigynia spreading at maturity; lower sheaths not fllamentose; culms bluntly 



triangular below the spikes. 161. C. rostrata. 



Lo wer perigynia reflexed; bracts many times exceeding the spikes. 



162. C. retrorsa. 



1. NARDINAE Kiikenth. Very densely cespitose. Leaf-blades filiform. 

 Spike solitary, linear-oblong, androgynous, densely flowered, bractless. Peri- 

 gynia ascending, biconvex, elliptic-ovate, not inflated, the walls thin, glabrous, 

 striate, stipitate, the beak hyaline-tipped, in age bidentulate. Achenes lenticular 

 or triangular. Stigmas 2 or 3. 



1. C. Hepburnii Boott. Culms 2-15 cm. high; sheaths strongly hyaline- 

 margined above, abruptly contracted into the blades; spike 5-12 mm. long, with 

 1-10 perigynia; scales ovate, acutish, the midvein conspicuous; perigynia 3 mm. 

 long; achenes usually triangular. C. nardina Auth., in part. C. stantonensis 

 M. E. Jones. Dry alpine slopes: Alta. Colo. Wash. B.C. Alp.Subalp. 

 Jl-Au. 



2. INFLATAE Kiikenth. Cespitose, the rootstocks elongate. Leaf-blades 

 filiform. Spike solitary, ovoid, androgynous, densely flowered, bractless. 

 Perigynia inflated, the walls very thin, slightly nerved, sessile, the smooth beak 

 hyaline tipped, obliquely cut, in age bidentulate. Achenes triangular. Stigmas 

 three. 



2. C. Engelmannii Bailey. Culms 5-20 cm. high; leaf-blades about 0.5 

 mm. wide; spike with 15-40 ascending perigynia; scales 1-nerved, acute to cuspi- 



