CYPERACEAE. 



69 



Stems equalling or exceeding the leaves; lowest 

 bract not colored nor auricled at base; perigynia 

 3-8. 

 Plant stoloniferous; none of the flowering stems short 

 and hidden among the leaves; spikes dark. 

 Perigynia obovoid, whitish. 

 Perigynia ellipsoid, brown at base. 

 Perigynia glabrous or merely granular-roughened. 



Beak of membranaceous somewhat inflated perigynium 

 deeply bidentate, the long teeth sharp and rigid; 

 leaves conspicuously nodulose. 

 Pistillate spikes drooping. 

 Pistillate spikes erect or ascending. 



Perigynia shiny, ascending, much inflated, 10 mm. 



long. _ 

 Perigynia not shiny, spreading, not much inflated, 

 4-8 mm. long. 

 Beak of perigynium wanting or if present entire or merely 

 emarginate, or if bidentate the teeth short; leaves 

 not conspicuously nodulose. 

 Stigmas 3 and akenes 3-angled. 



Spikes narrowly cylindrical, 6-10 cm. long; peri- 

 gynia granular, spreading; leaves 1-2 cm. broad. 

 Spikes not so long and slender; perigynia smooth; 

 leaves not so broad. 

 Perigynia spreading, the beak bidentate. 

 Perigynia not spreading, the beak entire or 

 emarginate, scarcely bidentate. 

 Terminal spike pistillate above, staminate 

 below. 

 Spikes erect; scales obtusish; perigynia 



inflated, 3 mm. long. 

 Spikes more or less drooping; scales 

 sharp-pointed; perigynium not 

 inflated. 

 Scales acute or acuminate; perigynia 



nerveless, 3.5 mm. long. 

 Scales mucronate; perigynia nerved, 

 5 mm. long. 

 Terminal spike wholly staminate. 



Pistillate spikes slender peduncled, 

 usually drooping. 

 Scales acute or cuspidate, about as 

 long as the perigynia. 

 Staminate spike linear; scales 

 pale; leaves 1-3 mm. broad; 

 rootstock creeping. 

 Staminate spike oblong-cylindric; 

 scales dark; leaves 4-8 mm. 

 broad, tufted. 

 Scales cuspidate or aristate, much 

 longer than the perigynia. 

 Perigynia broadly ovate to orbi- 

 cular. 

 Perigymia elliptic-lanceolate. 

 Pistillate spikes erect. 



Scales brown; leaves 2-5 mm. broad. 

 Scales pale. 



C. rossii. 



C. vespertina. 

 C. verecunda. 



C. comosa. 



C. exsiccata. 

 C. ulriculata. 



C. amplifolia. 

 C. oederi. 



C. accedens. 



C. atrata. 

 C. mertensii. 



C. limosa. 

 C. spectabilis. 



C. paupercula. 

 C. macrochaeta. 



C. ablala. 



