CYPEEACEAE 53 



spikes 4-10, globose : perigynia orbicular-ovate, li" long, not nerved, 

 shorter than the scale. — In dry ground near Lee's Summit and Courtney. 

 May-June. Our form is var. Xalapensis (Kunth) Britton. 



45. C. steiilis Willd. Culms 8'-20' high : leaves leas than 1" wide : 

 spikes 3-5, several-many-flowered, usually separate, the staminate flow- 

 ers usually numerous : perigynia ovate-lanceolate, IJ" long, nerved, 

 tapering into a sharp, rough beak, half the length of the body, longer 

 than the scale. — Prairie near Lee's Summit. May-June. 



46. C. Muskingumensis Schwein. Stout culms, 2°-3° high : leaves 

 2^" wide or less : spikes distinct, light brown, 6"-12" long, oblong- 

 cylindric, many-flowered : perigynia linear-lanceolate, 3" -4'' long, much 

 longer than the scale. — In swampy ground near Lake City and Sibley- 

 May-June. 



47. C. tribuloidea Wahl. l°-3° high : leaves about 2" wide : spikes 

 6-20, short-oblong, truncate at summit, 3"-6" long, W-V wide : peri- 

 gynia 2'''-3''' long, lanceolate, ascending or erect, twice the length of tbe 

 scale. — In moist meadows throughout. May-June. 



Var. turbata Bailey. Spikes 3" long, 2\" wide, ovoid-oblong : head 

 V-V long, the lower spike separated^ — Low grounds from Sheffield to 

 Sibley. 



48. C. scoparia Sohk. Culms l°-2i° high : leaves about \" wide : 

 spikes 3-8, brownish, 3"-8" long, oblong-conic, close together, usually 

 bractless : perigynia 2"-3" long, lanceolate, erect or ascending, longer 

 than the scale. — Common on prairies near Waldo Park, Lee's Summit and 

 Atherton. June. 



49. C. cristatella Britton. Culms 1 J°-3° high : leaves iy'-2" wide : 

 spikes 6-15, globular, 2"-3''' long, contiguous : perigynia lJ"-2" long, 

 ovate-lanceolate, spreading or ascending, their points conspicuous, much 

 longer than the scale. — Common in low meadows and thickets. May- 

 June. 



50. C. straminea Willd. Culms l°-3° high : leaves f''-2" wide : 

 spikes 3-8, globular, Z"-i" broad, distinct : perigynia \\" long, ovate, 

 wing-margined, ascending or spreading, exceeding the scale. — Infre- 

 quent In woods. Our form is var. miraftj'Zis (Dewey) Tuckerm. May- 

 June. 



51. C. festucacea Willd. Culms stiff and erect, l°-3°high: leaves 

 \"-^" wide : spikes 3-8, Z"-b" broad, greenish-brown, oblong to globu- 

 lar, contiguous, short-braoted : perigynia orbicular, broadly margined, 

 1 J" long, ascending, about the length of the scale. — Common in open 

 grounds. May-June. 



52. C. Bicknellii Britton. Culms 2°-4° high : leaves W-21" wide: 

 spikes 3-7, 4."~6" long, ovoid, silvery-green, close together : perigynia 

 orbicular, strongly winged, 2' '-3" long. — Frequent in dry or wet open 

 grounds throughout. May-June. 



