CAREX KEY. SEDGE FAMILY. 359 



Culms phyllopodic. 



Perigynia beak if present not bidentate. 



Culms single or in small clumps, strongly stoloniferous ; scales very dark with slender mid- 

 vein ; strict and generally low species. 



Leaves with revolute margins ; perigynia at most obscurely nerved. 184. C. concolor. 

 Leaves with involute margins; perigynia conspicuously nerved. 185. C.. Goodfnowii. 

 Culms densely cespitose, the stolons absent or not prominent ; scales with broad light-colored 



center ; tall slender species. 



Leaves H"-i}" wide; staminate spike one; rootstocks not sending out long stolons. 



1 86. C. lenticularis. 



Leaves broader; staminate spikes two or more; stolons long. 187. C. aquatilis. 

 Perigynia beak markedly bidentate; perigynia strongly ribbed. 188. C.nebraskensis. 



53. CRYPTOCARPAE. 

 Pistillate spikes strictly erect, the upper sessile or nearly so ; perigynia coriaceous. 



Leaves i)4" wide or less, the margins involute; lowest bract somewhat spathe-likc ; pistillate 



spikes- few-flowered; culms 7' or less high. 189. C. siibspathccca. 



Leaves i"-3" wide, flat or with revolute margins; lowest bract not spathe-like ; pistillate spikes 



many-flowered ; culms usually taller. 

 Scales little longer than perigynia, pale reddish ; pistillate spikes usually 4' long ~*- less. 



190. C. si-i.na. 

 Scales much exceeding perigynia, dark purple, light brownish or chestnut ; pistillate spikes 



\y\'-z' long. 191. C. recta. 



Pistillate spikes peduncled, drooping, widely spreading or suberect. 



Pistillate scales purplish brown ; perigynia coriaceous. 192. C. cryptocarpa. 



Pistillate scales lighter colored ; perigynia membranaceous. 



Awns -of pistillate scales erect or appressed-ascending ; perigynia not inflated; basal sheaths 



little or not at all fibrillose. 193. C. maritima. 



Awns of pistillate scales spreading or loosely-ascending ; perigynia generally somewhat 



inflated ; basal sheaths fibrillose. 



Sheaths rough hispid; lower pistillate scales tapering into awn. 194. C.gynandra. 

 Sheaths smooth; lower pistillate scales abruptly contracted into awn. 195. C. crinita. 



54. HIRTAE. 

 Staminate scales not ciliate. 



Perigynia beak much shorter than body, the teeth l / 2 " long or less. 

 Perigynia glabrous to sparsely pubescent. 

 Leaves 3"-6" wide, flat. 



Culms aphyllopodic, strongly purplish tinged and filamentose at base ; mature peri- 

 gynia strongly nerved. 196. C. lacustris. 

 Culms phyllopodic, not purplish tinged or filamentose at base ; mature perigynia im- 

 pressed nerved. 197. C.impressa. 

 Leaves i"-2" wide, becoming involute. 198. C. Walteriana. 

 Perigynia densely or strongly pubescent. 



Perigynia nerves obscured by dense pubescence, the teeth of beak short. 



Perigynia beak with hyaline orifice at length somewhat bidentate ; staminate spike 



usually one, sessile or short-stalked. 199. C.vestita. 



Perigynia beak with non-hyaline, strongly bidentate orifice ; staminate spikes long- 

 stalked. 



Leaves flat, more than i" wide. 200. C.lanuginosa. 



Leaves involute, i" wide or less. 201. C.lasiocarpa. 



Perigynia nerves prominent, the teeth of beak prominent, slender. 202. C. Houghtonii. 

 Perigynia beak including teeth nearly as long as body, the teeth 34" long or more. 



Perigynia glabrous or pubescent, ovoid, the teeth less than i" long, erect or spreading; scales 



acute to aristate. 203. C. trichocarpa. 



Perigynia glabrous, lanceolate or ovoid-lanceolate, the teeth i"-2" long, widely spreading; 



scales long-aristate. 204. C. atherodes. 



Staminate scales strongly ciliate. 205. C. hirta. 



55. FLAVAE. 



Bracts long-sheathing, erect ; pistillate spikes scattered. 206. C. fulvescens. 



Bracts except lower not long-sheathing, widely spreading ; pistillate spikes, at least upper, approximate. 

 Leaves involute ; perigynia ascending, not yellowish. 207. C. extensa. 



Leaves not involute ; perigynia squarrose, yellowish. 



Perigynia i"-i I / 2 " long, the beak scarcely half length of body. 208. C.Oederi. 



Perigynia 2"-3" long, the beak about length of body. 



Scales hidden ; perigynia 2" long ; beaks spreading or lower reflexed. 209. C. lepidocarpa. 

 Scales conspicuous ; perigynia 2 l / 2 "-$" long, the beaks spreading in all directions. 



210. C.fiava. 

 56. COLLINSIAE. Represented by i species. 211. C.Collinsii. 



57. FOLLICULATAE. 



Leaves i"-2" wide; scales acute or short acuminate. 212. C.abacta. 



Leaves 2"-8" wide; scales strongly awn-tipped. 213. C.folliculata. 



58. PHYSOCARPAE. 



i. Perigynia scarcely inflated ; beak entire or emarginate ; stigmas usually two ; achenes lenticular. 

 Leaves strongly involute, l / 2 "-i l / 2 " wide; rootstocks creeping, the culms arising one-several 



together ; spikes sessile or short-peduncled ; culms often somewhat filamentose at base. 

 Pistillate spikes linear- or oblong-cylindric, 2"-2j4" wide; perigynia loosely ascending; leaves 



i" wide or less. 214. C. miliaris. 



Pistillate spikes suborbicular to oblong, wider; perigynia appressed-ascending; leaves mostly 



wider. 215. C.rhomalca. 



Leaves flat, wider : rootstocks not creeping, but plants freely stoloniferous ; culms not filamen- 

 tose at base; spikes from nearly sessile to strongly peduncled. 216. C.saxatilis. 



