10. Carex fissa Mack. Fig. 258. 



Cespitose; rootstock short, stout, black, fibrillose; culms 2.5-7.5 dm. long, 4-7 

 mm. wide at base, bluntly triangular, smooth or roughened beneath head, light- 

 brown at base; well developed leaves 4 to 6 to a culm, on lower third; blades 1-2 

 dm. long, 3-5 mm. wide, flat or channeled, thick, light-green; sheaths thin and 

 cross-rugulose ventrally, prolonged, red-dotted near mouth; ligule wider than long; 

 spikes 10 to 20, androgynous, in a head 2.5-4 cm. long and 8-18 mm. wide; lower 

 bracts setaceous, the upper scalelike; scales acute or cuspidate, hyaline, light- 

 yellowish-brown-tinged with green midvein; staminate flowers inconspicuous; peri- 

 gynia 8 to 20 in a spike, 3.5 mm. long and 2 mm. wide, ascending or spreading, 

 piano- or concavo-convex, submembranous. light-green or yellowish-brown-tinged, 

 few-nerved dorsally, sharp-margined, serrulate above, substipitate; beak 1 mm. 

 long, serrulate, dorsally cleft, bidentate, light-reddish-brown-tinged; achenes 2 mm. 

 long, 1.7 mm. wide, lenticular, substipitate, apiculate, jointed with the short style 

 which is enlarged at base; stigmas 2, reddish-brown. 



On wet ditch banks in Okla. ( Waterfall) . 



11. Carex crus-corvi Kunze. Fig. 259. 



Densely tufted perennial (the internodes of the rhizomes very short); culms 

 4-9 dm. long, 4-12 mm. thick basally, soft; sheaths soft, ventrally thin-papery 

 and easily splitting, the orifice horizontal or shallowly U-shaped, not thickened; 

 blades long, often surpassing the inflorescence; inflorescence a decompound pan- 

 icle 6-15 (-19) cm. long and 15-40 mm. thick, with 7 to 13 ascending or erect 

 short branches (the lower-middle branches the longest), each branch with 3 to 

 10 burlike sessile androgynous bractless spikes each with only a few perigynia; 

 scales lanceolate, about as long as or slightly exceeding the body; perigynial body 

 triangular, largely plano-convex, 2-3 mm. long, firm, brownish, basally inflated, 

 discolored whitish, truncately narrowed to the minute stipelike base, apically 

 passing into the linear strongly bidentate beak (3-4 mm. long); achene lenticular, 

 up to 2 mm. long, 1 .3 mm. wide. 



In mud on edge of lakes, ponds and streams, and in shallow water, in Okla. 

 (McCurtain, Choctaw and Love cos.), frequent in e. Tex., infrequent in s.e. and 

 n.-cen. Tex., rare in the Plains Country (Wichita Co.), spring; Gulf States and 

 n. in cen. U.S. to O., Mich., Minn, and Wise. 



12. Carex stipata Muhl. Fig. 260. 



Densely tufted perennial, the internodes of the rootstocks very short; culms 

 3-10 dm. long, 3-7 (-12) mm. thick basally, rather soft, triangular above with 

 concave sides; sheaths soft, ventrally not transversely wrinkled, easily splitting, 

 orifice horizontal or slightly prolonged and rounded, not thickened; upper blades 

 usually about equaling the inflorescence; inflorescence a dense decompound pan- 

 icle 3-10 cm. long and 10-25 mm. thick, with several ascending branches (the 

 lower branches longer), each branch with 2 to 10 sessile subglobose essentially 

 bractless androgynous spikes each with 8 to 15 perigynia; scales ovate, acuminate, 

 about equaling the perigynia; perigynia 4-6 mm. long, the bodies plano-convex, 

 ovate, firm, 2-3 mm. long, basally more or less discolored brownish-stramineous, 

 firmer, abruptly narrowed to a minute stipe, apically passing into the linear beak 

 which is strongly bidentate and 2-3 mm. long; achene lenticular, about 1.7 mm. 

 long, 1.5 mm. wide. Incl. var. maxima Chapm., C. uberior (Mohr) Mack. 



In mud on edge of streams and ponds, wet meadows and marshes, in Okla. 

 (McCurtain Co.), rare in e. Tex. (Austin and Leon cos.), N.M. (Catron, San 

 Miguel, Colfax and Sandoval cos.) and Ariz. (Apache, Navajo, Coconino, Graham 

 and Gila cos.), spring; most of temp. N.A. (except extreme s.w. U.S. and Mex.). 



506 



