CYPERACEAE (SEDGE FAMILY) 



213 



Spikes all sessile and approximate ; perigynia obovold, 

 prominently ribbed, retuse, with a distinct short 



entire beak 109. C. abbreviate. 



Lowest spike peduncled ; perigynia narrowly obovoid, 

 faintly nerved or nerveless, narrowed to the beakless 



tip 



q. Perigynia distinctly beaked w. 



w. Spikes sessile, or the lowermost short-pedlceled, erect or 

 oblique ; the bracts very long and much exceeding the 

 inflorescence, rarely 5 mm. broad. 



Leaves Involute 



Leaves flat. 



Beak about equaling body of perigynlnm .... 

 Beak much shorter than body of perigynium . . . 

 to. Spikes mostly long-pediceled, spreading or drooping, If ses- 

 sile and erect the bracts more than 5 mm. wide as. 

 x. Leaves broad (usually 5 mm. or more); scales strong- 

 ribbed ; spikes dense, the perigynia firm, dull, wide- 



110 C.paUetcem. 



187. C. extenna. 



188. C.flara. 



189. C.'Oederi. 



spreading y. 

 Leaves soft, ribbon -like, dark green ; lower bract 5-10 



mm. wide, much exceeding the inflorescence . . 150. <7. ncabrata. 

 Leaves firm, glaucous ; lower bract 1-4 mm. wide, about 



equaling the inflorescence. 

 Perigynia spreading-ascending, glaucous, faintly-nerved 



or nerveless, gradually tapering to the short beak . 148. C. verrucosa. 



Perigynia squarrose, deep green or brownish, strongly 



149. C. macrokolea. 



141. C. longirostrh. 



143. C. cantanea. 



144. C. capillaris. 



many-ribbed, abruptly beaked 



(B. Leaves narrow (usually less than 5 mm. wide) ; scales thin, 

 nerveless or slightly nerved ; spikes loosely flowered, 

 the thin lustrous perigynia strongly ascending e. 

 e. Perigynia abruptly contracted to an awl-shaped beak 



as long as the body . 



. Perigynia gradually contracted to the beak. 



Leaves pubescent; pistillate spikes 6-S mm. thick 

 Leaves glabrous ; pistillate spikes 24 mm. thick . . 

 3. Lowest foliaceous bract of the inflorescence with a prominent closed 



green sheath a. 



a. Perigynia nerveless or with few nerves most prominent toward 

 the base, not uniformly and conspicuously nerved from base 

 to orifice (excepting the marginal nerves) b. 

 b. Plant caespitose, scarcely stoloniferous, the rootslock short and 



thick ; perigynia with long-attenuate beaks e. 

 e. Perigynia abruptly contracted to a slender beak as long as the 

 body. 



Perigynia hairy, remote . . . 140. C. attiniboinentts. 



Perigynia smooth, approximate 141. C. tongiroatris. 



c. Perigynia gradually contracted to the beak d. 

 d. Pistillate spikes oblong-cylindric, densely flowered. 

 Spikes 5-10 mm. thick. 



Leaves glabrous ; scales white 142. <?. cherokeenri*. 



Leaves pubescent ; scales brown 148. C. ca&tanea. 



Spikes 2-4 mm. thick. 



Plant 0.5-1.5 dm. high; spikes approximate . . . 144. C. capillarin. 

 Plant taller; spikes remote .... (144) C. capillari*, v. elon gata, 

 d. Pistillate spikes linear-cylindric e. 



e. Basal sheaths reddish-purple or castaneous /! 

 /. Basal leaves 6-10 mm. broad, scabrous at base ; peri- 

 gynia stipitate, ovoid-trigonous .... 

 f. Basal leaves 3-7 mm. broad, smooth at base ; peri- 

 gynia fusiform, obscurely trigonous 

 Perigynia glabrous. 



Perigynia mostly overlapping. 

 Perigynia 6-9 mm. long, twice as long as the 



white scales 



Perigynia 4.5-6.5 mm. long; the scales straw- 

 color or greenish-brown. 

 Perigynin twice as long as the scales ; leaves 2-4 



mm. wide (146) C. debilis, v. Rvdgei. 



Perigynia one third longer than the scales ; leaves 



4-6 mm. wide (146) C. debilis, v. strictinr. 



Perigynia alternate and mostly remote, not over- 

 lapping (146) C. debilis, v. interjeeta. 



Perigynia hairy (146) C. deftili*, v. pubera. 



e. Basal sheaths dull pale brown .... (12T) C. laaeiflora, v. leptonervia. 

 b. Plant loosely stoloniferous, the elongate rootstock slender; 

 perigynia beakless or with short or abrupt beak g. 



g Perigynia hairy 108. C. caryophyllea. 



g Perieynia not hairy h. 

 h. Perigynia beakless or with a very short oblique tip 4. 



145. C. arctata. 



146. C. debilis. 



