70 CYPERACEAE. 



Leaves 4-7 mm. wide; spike very 



loose. C. hendersom. 



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. scop-nlorum. 

 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. /;<//</. 



Spikes 3-4 cm. long; perigynia 



compressed, straw-colored. C. angustata 



