CYPERACEAE 53 



spikes 4-10, globose: perigcynia orbicular-ovate, IV^ long, not nerved, 

 shorter than the scale. — lu 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 less than V wide : 

 spikes 3-5, several-raany-flowered, usually separate, the stamiuate flow- 

 ers usually numerous: perigynia ovate-lanceolate, \Y^ 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 

 2Y^ wide or less : spikes distinct, light brown, Q'^-\2'' long, oblong- 

 cylindric, many-flowered : perigynia linear-lanceolate, Z^' -A'' long, much 

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

 May-June. 



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

 6-20, short-oblong, truncate at summit, 3^^-6^^ long, 3'^-4^^ wide : peri- 

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

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



Yar. turbata Bailey. Spikes 3'^ long, 2Y^ wide, ovoid-oblong : head 

 l'-2' long, the lower spike separated. — Low grounds from Shefiield to 

 Sibley. 



48. C. Bcoparia Schk. Culms l°-22° high : leaves about V^ 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. criatatella Britton. Culms li°-3° high : leaves \V^-2'' wide : 

 spikes 6-15, globular, 2'^-3^^ long, contiguous : perigynia \Y^-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, 3'^-4^^ broad, distinct : perigynia IV^ long, ovate, 

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

 quent in woods. Our form is var. m«>a6i7/s (Dewey) Tuckerm. May- 

 June. 



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

 ]^//_2// ^ide : spikes 3-8, 3^^-5^^ broad, greenish-brown, oblong to globu- 

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

 \Y^ long, ascending, about the length of the scale. — Common in open 

 grounds. May-June. 



52. C. Bicknellii Britton. Culms 2°-4° high : leaves W'~2Y^ 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. 



