318 American Midland Naturalist Monograph No. 7 



18. Plants loosely stoloniferous, the stems solitary, 

 10-30 cm tall; leaves often folded, 1.5-3 



mm wide; sandy soil, n.e. Ill 



C. crawei Dewey 



18. Plants tufted, 30-60 cm tall; leaves 3-9 mm 

 wide; moist meadows and woods, common. 



[C. rectior Mack. ; C. haleana Olney] 



C. granulans Muhl. 



7. Mature perigynia faintly imjDressed-nerved or nerveless; 



spikes erect or ascending. 



19. Terminal spike staminate; pistillate glumes mucronate 



or awned. 



20. Sheaths and lower blades pubescent; perigynia 2.5- 



3 mm long; moist ground, rare; "N. Illinois", 



Vasey C. pallescens L. 



20. Plants glabrous; perigynia 3.5-5.5 mm long. 



21. Perigynia 1.5 mm wide; bract-sheaths with ser- 

 rulate margins; peduncles of the pistillate 

 spikes scabrous; meadows and ditches in the 

 n. half of 111., not common ....C. conoidea Schk. 

 21. Perigynia 2-2.5 mm wide; bract-sheaths and 

 peduncles smooth or nearly so. 

 22. Pistillate spikes 3- to 12-flowered; leaves 

 thin, soft, not glaucous. 



23. Perigynia 4.5-5.5 mm long; stems brown- 

 ish at base; leaves 4-8 mm wide; 

 woods, thickets, and meadows, com- 

 mon C. grisea Wahl. 



23. Perigynia 3.5-4.5 mm long; stems reddish 

 at base; leaves 2-4 mm wide; dry banks 

 and wooded hillsides, rare; Cook, Du 



Page, and Stark counties 



C. aniphibola Steud. 



22. Pistillate spikes 12- to 35-flowered; leaves 

 glaucous, thick, firm; awn of the pistillate 

 glumes smooth; woods, local [C. glaucodea 

 Tuckerm.] (Although not closely related, 

 C. X fulleri Ahles, Rhodora 58: 320, 1956, 

 from Winnebago Co. might be sought 

 here.) C. flaccosperma Dewey 



19. Terminal spike gynecandrous, or at least with some 

 pistillate flowers. 



24. Perigynia elliptical, light green, granular, much 

 shorter than the purplish-black cuspidate glumes; 

 leaves 1.5-4 mm wide; plants stoloniferous, grow- 

 ing in bogs and marshy ground in n. Ill 



C. buxbaumii Wahl. 



