CAREX. CLX. CYPERACE^E. 581 



bifid, concavo-convex, scabrous on the margin, longer than the oblong, lanceo- 

 late glume ; st. 1 3f high, acutely triangular. Plant yellowish-green. Com- 

 mon in fields and meadows on colder soils. 



38. C. TENUIFLORA. Wahl. 



Spikelets 2 3, ovate, clustered, sessile, alternate, lower one biacteate; 

 perig. ovate-oblong, acutish, plano-convex, equaling the oblong-oval e, hyaline 

 or white glume ; st. a foot or more high, slender, subprostrate, longer than the 

 flat and narrow leaves. Light green. Spikelets whitish. Burlington and 

 Salem, Vt., in swamps, Robbing Oriskany and Ogdensburg, N. Y., Kneirskern, 

 Southampton, Mass., Chapman. 



39. C. CYPEROlDES. 



Spikelets ovate, closely aggregated into a head, with long and leafy bracts; 

 perig. ovate, long-lanceolate, or drawn into a long awn scabrous on its edges, 

 slightly stipitate, 2-toothed, a little longer than the lanceolate and cuspidate 

 glume ; plant very pale green. Jefferson Co., N. Y. first found in our country 

 last summer, by Dr. Crawe. 



40. C. MUSKINGUMENSIS. Schw. 



Spikelets oval-oblong, 5 10, somewhat tapering at both ends, large and 

 approximate, close-flowered, dry and chaff-like ; pcrig. lanceolate, compressed, 

 thin, distinctly winged, birtentate, nerved, acuminate, twice longer than the 

 ovate-lanceolate glume ; plant light green in all its parts. Common in Ohio 

 and Mich., 1836' high. 



41. C. LIDDONI. Boott. 



Spikelets 5 7, oblong-ovate, closely aggregated ; perig. ovate, lanceolate, 

 acuminate, oblique at the orifice, glabrous, on the margin serrulate, scarcely 

 longer than the ovate-lanceolate glume, which is acute and hyaline on the edges ; 

 perig. and glumes rather chestnut brown ; plant yellowish-green. Arctic Am., 

 Boott; Mich., Dr. Cooley. 



C. Stamens and Stigmas on separate spikes. 

 1 Staminate spike single. 



42. C. AUREA. Nutt. (C. pyriformis. Schw.) 



c? Spike short, cylindric, pedunculate ; 9 spikes 3, oblong, loose-flowered, 

 subpendulous, exsertly pedunculate, subapproximate, bracteate ; perig. globosej 

 obovate or pear-form," obtuse, nerved, entire at the mouth, longer than the ovate, 

 acute or short-mucroaate glume; st. 310' high, slender, often subprocumbent. 

 Plant glabrous, green. Common in wet grounds. 



43. C. SAXATII.IS. 



tf Spike oblong, thick; 9 spikes 2 or 3, oblong, obtuse, sessile, lower pe 

 dunculate; perig. elliptic, plano-convex, obtuse, short-rostrate, about equaling 

 the oblong and obtuse glume ; st. 6 10' high, erect, with long and leafy sheath- 

 and bracts. Spikes nearly black. White Mts., N. H., Barratt ; woods, Vt.. 

 Pursh. 



44. C. CONCOLOR. R. Br. 



c? Spike erect, cylindric ; 9 spikes 2 3, erect, subsessile, cylindric ; perig. 

 oval, entire, smooth, mucronate, about equal to the oblong and obtuse glume; 

 si. 10 15' high, smooth, leafy below ; bracts auriculate ; <? spike sometimes 

 pistillate above. White Mts., N. EL, Boott. Closely related to C. caspitosa, L., 

 but has a smooth stem ; scales of light color. 



2. Staminate spikes one or mwe, and the upper part of the pistillate sometime* 



staminate. 



45. C. RIGIDA. Good. 



<? Spike oblong, cylindric, rarely 2; 9 spikes 2 3, oblong, cylindric, 

 densely-flowered, short and thick, approximate, lower one subpedicellate, with 

 a bract surpassing the stem ; perig. ovate, obtusish, entire at the orifice ; glume 

 nearly twice longer than the mature fruit and subequal before ; st. 3 8' high, 

 thick and stiff, often recurved ; Ics. stiff and glaucous. Ipswich, Ms., Oake< 

 Elas been confpounded with C. cees-pitosa. 



