70 CYPERACEAE. 



Leaves 4-7 mm. wide; spike very 



loose. C. hendersoni. 



Leaves 2 mm. wide; spike dense. 

 Perigynium beakless; leaves 



glaucous. C. livida. 



Perigynium with a beak half 

 as long as body; leaves not 

 glaucous. C. californica. 



Stigmas 2 and akenes lenticular. 



Perigynium plump, not angled, beakless. 



Mature perigynia subglobose or pyriform, not 

 stipitate, glabrous, somewhat fleshy, trans- 

 lucent, strongly nerved. C. aurea. 

 Mature perigynia obovoid, stipitate, pulveru- 

 lent, not fleshy nor translucent. C. celsa. 

 Perigynium compressed, plano-convex or biconvex, 



the beak entire or emarginate. 

 Scales pointed, longer than the perigynia. 



Perigynia granular-roughened, 2-5 mm. 

 long; pistillate spikes slender, ascending, 

 often cernuous; scales a little longer than 

 the perigynia. C. sitchensis. 



Perigynia not granular-roughened, 3 mm. 

 long; scales much longer than the peri- 

 gynia. 



Pistillate spikes nodding; perigynia el- 

 liptic, pale, dull, not turgid. C. cryptocarpa. 

 Pistillate spikes ascending or erect; peri- 

 gynia nearly orbicular, dark, shiny, 

 turgid. C. magnified. 

 Scales not longer than the perigynia; spikes 



erect. 

 Lowest leaves of the flowering stems reduced 



to sheaths. 



Perigynia ovoid, 2 mm. long; scales pale; 

 pistillate spikes often very loose at 

 base. C. interrupta. 



Perigynia ellipsoid, 3 mm. long; scales 



dark; spikes dense. C. nudata. 



Lowest leaves of the flowering stems bearing 



blades. 

 Perigynia obscurely nerved; scales dark 



purple. 



Beak of perigynium bent to one side. C. scopulorum. 

 Beak of perigynium straight. 



Scales as long and broad as the 



perigynium. C. rigida. 



Scales shorter and narrower than 



the perigynia. C. gymnoclada. 



Perigynia strongly nerved; scales purple. 

 Scales not obtuse, about as long as the 



perigynia. 



Spikes 1.5-2.5 cm. long; perigynia 

 strongly biconvex and brown 

 when mature. C. aperta. 



Spikes 3-4 cm. long; perigynia 



compressed, straw-colored. C. angustata 



