Carex 



Cyperaceae 



227 



Sheaths not thickened at the mouth, cross-rugulose ventrally, easily broken, pro- 

 longed upward at the mouth. 

 Perigynium 4-5 mm long, the beak about the length of the body ; leaf blades 4-8 



mm wide 20. C. stipata. 



Perigynium 5-6 mm long, the beak longer than the body; leaf blades 8-15 mm 



wide 20a. C. stipata var. maxima. 



Sheaths thickened (often cartilaginous) at the mouth, rarely cross-rugulose ven- 

 trally, not easily broken, concave or truncate at the mouth 



21. C. laevivaginata. 



Perigynium 6-7 mm long, abruptly enlarged below into a disklike base, obscurely 

 nerved ventrally except at the base, the beak 2-3 times the length of the body; 



sheaths dotted with purple ventrally 22. C. Grus-corvi. 



Perigynium contracted into a beak not longer than the body, the body nerveless ven- 

 trally except sometimes at the base. 

 Sheaths not cross-rugulose ventrally; spikes yellowish or tawny at maturity; per- 

 igynium narrow, faintly nerved dorsally, the beak about the length of the body. 



23. C. alopecoidea. 



Sheaths cross-rugulose ventrally; spikes green; perigynium broad, usually strongly 



nerved dorsally, the beak generally about half the length of the body 



24. C. conjuncta. 



20. Carex stipata Muhl. Map 439. Very common in wet habitats 

 throughout Indiana. It is usually found on borders of ponds and streams 

 and in low woods, roadside ditches, swamps, marshes, bogs, and woodland 

 swales. 



Newf. to Alaska, southw. to N. C, Tenn., Kans., N. Mex., and Calif. 



20a. Carex stipata var. maxima Chapm. (Carex stipata var. uberior 

 Mohr and Carex uberior (Mohr) Mack.) Map 440. Rare; it is usually 

 found on the borders of ponds and streams, in low woods, roadside 

 ditches, swamps, marshes, bogs, and woodland swales. 



In the western portion of its range transitional forms between this plant 

 and C. stipata occur with a frequency which discourages attempts to main- 

 tain it as specifically distinct. Of the five collections known from Indiana 

 three are typical of var. maxima in all their characters while two (Deam 

 no. 36082, with leaves averaging only 7 mm wide, and Deam no. 38688, 



