82 American Midland Naturalist Monograph No. 2 



21. Perigynia 3.5-4.5 mm. long; awn of the pistillate 

 glumes smooth; stems reddish at base; leaves 2-4 

 mm. wide; dry banks and wooded hillsides, rare; 

 Stark Co., V. H. Chase C. amphibola Steud. 



20. Pistillate spikes 12-35-flowered; leaves strongly glau- 

 cous, thick, firm; awn of the pistillate glumes 



smooth; open woods, and roadsides, local 



C. glaucodea Tuckerm. 



17. Terminal spike gynecandrous. 



22. Perigynia elliptical, light green, granular, much shorter than 

 the purplish black cuspidate glumes; leaves 1.5-4 mm. 



wide; plants stoloniferous, growing in bogs, n. Ill 



C. biixbaumti Wahl. 



22. Perigynia obovate-orbicular, slightly wrinkled, about equalling 

 the reddish brown acute or obtuse glumes; leaves 4-9 mm. 

 wide; plants cespitose, growing in moist woods, thickets, 

 and roadside ditches, common C. shortiana Dewey 



5. Beak of the perigynium curved, or if straight 0.7-1 mm. long; glumes 

 mucronate or aristate. 

 23. Beak oblique or abruptly curved, 0.3-0.5 mm. long. 



24. Stems purplish tinged at base; lower pistillate spikes en long 

 capillary peduncles; perigynia 2.5-3.2 mm. long; woods, not 



uncommon. [C. laxiflora var. gracillima Boott} 



- C. gracilescejis Steud. 



24. Stems brownish at base; lower pistillate spikes short-peduncled; 



perigynia 3-4 mm. long, woods, common. [C. laxiflora var. 

 blanda (Dewey) Boott] C. blanda Dewey 



23. Beak straight, 0.7-1 mm. long; perigynia 40-50-nerved. 



25. Sheaths pubescent; perigynia 4-5 mm. long; leaves 3-7 mm. 



wide; wooded hillsides, rare; near Peoria, Brendcl, McDonald; 

 Stark Co., V . H. Chase C. hitchcockiana Dewey 



25. Sheaths glabrous; perigynia 3-4 mm. long; leaves 2-4.5 mm. wide; 

 dry woods in tbe n. half of the state C. oligocarpa Schk. 



Group VI 



Stigmas three; achenes trigonal; spikes two or more; perigynia glabrous, 

 the beak sharply bidentate. 



1 . Staminate spike solitary or none; sometimes th'e terminal spike bearing some 

 pistillate flowers. 



2. Mature perigynia 1-2 cm. long. 



3. Pistillate spikes globose, the ellipsoid perigynia widely radiate-sp-ead- 

 ing; beak of the perigynium 1.5-2.5 mm. long; moist woods, common 

 C. grayii Carey 



3. Pistillate spikes ellipsoid to cylindrical, the ovoid-lanceoloid perigynia 

 ascending; beak of the perigynium 5-10 mm. long. 



