SEDGE FAMILY 119 



Perlgynia deiisclv or strongly piibi'scent. 



Nerves of the pci it,'vnhi oliscurod by pubescence, the teeth of beak short. 

 Leaf-blades thu. more than 2 mm. wide. 143. C. lanuginosa. 



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



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



145. C. Iloughtonii. 

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

 more. 

 Perlgynia glabrous. 



Perlgynia ovoid, the teeth less than 2 ram. long, erect or spreading; scales acute 



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



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

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



147. C. atherodes 

 Perigynia hairy. 148. C. Shcldonii. 



4.3. EXTENSAE. 



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



149. C. viridula. 

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



44. P.\UCIFLORAE. 



Rhacheola present, conspicuously e.xserted; culms with many leaves. 



151. C. rnicroolochin. 

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



152. C. pauciflora. 



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 mtich inflated; beak bidentate; stigmas normally three and 

 achenes triangular. 

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



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



Lower perigynia not refle.Ked ; bracts moderately e.xceeding the spikes. 



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

 sharply triangtilar. 

 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. 



Lower perigynia reflexed; bracts many times exceeding the spikes. 



162. C. relrorsa. 



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 hyahne- 

 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 1.5-40 ascending perigynia; scales 1-nerved, acute to cuspi- 



