145. Cyperaceae 311 



Stems tufted. 



4. Perigynia subulate-lanceolate. 



5. Perigynia 4-5 mm long, the beak about the length of the 

 body; swamps and wet meadows C. stipata Muhl. 



5. Perigynia 5-7 mm long. 



6. Perigynium about 5 mm long, tapering gradually from base 



to apex; inflorescence 2.5-6 cm long; leaves 3-6 mm 



wide; swampy woods ....C. laevivaginata (Kiikenth.) Mack. 



6. Perigynium 6-7 mm long, abruptly enlarged below into a 



disc-like base; inflorescence 7-17 cm long; leaves 5-10 



mm wide; swampy ground C. cruscorvi Shuttlw. 



4. Perigynia oval, ovate-lanceolate, ovoid or ellipsoid. 



7. Spikes usually fewer than 12; inflorescence often capitate. 

 8. Leaves 1-4 mm wide; sheaths close. 



9. Perigynia spongy-thickened at the base. 



10. Perigynium with a minute beak 0.2 mm or less in 



length; bogs, n.e. Ill C. disperma Dewey 



10. Perigynium with a distinct beak 0.6-1 mm long. 



11. Beak entire-margined; glumes acuminate or cus- 

 pidate. 

 12. Body of the perigynium broadly ovate, deep 

 green, abruptly short-beaked; dry woods, 

 not common C. retroflexa Muhl. 



12. Body of the perigynium ovate-lanceolate, light 



green, tapering to the beak; dry woods, s. 



Ill C. texensis (Torr. ) Bailey 



11. Beak minutely serrulate along the edges. 



13. Broadest leaves 1-2 mm wide; perigynium 



tapering into the beak; stigmas long, slen- 

 der, usually not twisted ; woods and thickets, 



common C. rosea Schk. 



13. Broadest leaves 2-3 mm wide; perigynium 

 abruptly contracted into the beak; stigmas 

 short, stout, contorted, red; dry woods, 



common C. convoluta Mack. 



9. Perigynia not spongy-thickened at the base. 



14. Heads mostly 1.5-3.5 cm long; leaves and stems stiflf 

 and wiry; perigynia oval, 3-3.5 mm long, 2.5 mm 

 wide, the beak 0.5 mm long, serrulate; sandy soil, 

 often in open woods, in the northern half of 111. 



[Inch C. austrina (Small) Mack.] 



C. muhlenbergii Schk. 



14. Heads mostly 8-15 mm long; leaves and stems soft; 

 perigynia 2-3 mm long. 

 15. Perigynia oval, 1-1.5 mm wide, the serrulate beak 

 1 mm long; open woods or along roads, fre- 

 quent C. cephalophora Muhl. 



