CYPERACEAE (SEDGE FAMILY) 



213 



Spikes all sessile and approximate ; perigynia obovoid 

 prominently ribbed, retuse, with a distinct short 

 entire beak ,-^ • .• m. C. abbre'ciata. 



Lowest spike peduncled; pengynia narrowly obovoid, 

 faintly nerved or nerveless, narrowed to the beakless 



o • • ^^P*' ,^'^ :. A 110 C.palUHcms. 



q. Pengynia distmctly beaked w. *^ 



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

 oblique the bracts very long and much exceeding the 

 inflorescence, rarely 5 mm. broad. 

 Leaves involute ........ 137. C. externa. 



Leaves flat. 

 Beak about equaling body of perigynium .... 138. C. Hata 



Beak much shorter than body of perigyniurn . . . \2,^, C.Oederi 

 ic. Spikes mostly long-pediceled, spreading or drooping, if ses- 

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

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

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

 spreading y. 

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



mm. wide, much exceeding the inflorescence . . 150. C. acabrata 

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

 equaling the inflorescence. - 

 Perigynia spreading-ascending, glaucous, faintlv-nerved 



or nerveless, gradually tai)ering to the short beak . 148. C. nei-rucosa, 

 Perigynia squarrose, deep green or brownish, strongly 



many-ribbed, abruptly beaked ..... 149. C. macrokolea. 



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

 nerveless or slightly nerved ; spikes loosely flowered, 

 the thin lustrous perigynia strongly ascending s, 

 e. Perigynia abruptly contracted to an awl-shaped beak 



as long as the body ...... 141. C. longiroatris. 



z. Perigynia gradually contracted to the beak. 



Leaves pubescent; pistillate spikes 5-S mm. thick . 14S. C. castanea. 

 Leaves glabrous ; pistillate spikes 2-4 mm. thick . . 144. C. capillaris. 

 6. 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 rootstock short and 

 thick ; perigynia with long-attenuate beaks c. 

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

 body. 



Perigynia hairy, remote . . 140. C. a sHnihoinenHi. 



Perigynia smooth, approximate 141. C. longiroatris. 



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. C. cherokeensU. 



Leaves pubescent ; scales brown 143. C. castanea. 



Spikes 2-4 mm. thick. 

 Plant 0.5-1.5 dm. high ; synkes approximate . . . 144. C. capillaris. 

 Plant taller; spikes remote .... (144) C. capillarifi, \. elonyata. 

 a. 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 .... 145. C. arctaia. 

 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 14G C. debilis. 



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

 color or greenish-brown. 

 Perigynia twice as long as the scales ; leaves 2—4 



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



Perigynia one third longer than the scales ; leaves 



4-6 mm. wide (146) C. debilis, y. strictior. 



Perigynia alternate and mostly remote, not over- 

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



Perigynia hairy (146) C. debilis, v. pubera. 



e. Basal sheaths duU pale brown .... (\2X) 0. laxijlora, \. Ispionervia. 

 b. Plant loosely stoloniferous, the elongate rootstock slender; 

 perigynia beakless or with short or abrupt beak g. 



g. Perigynia hairy c . . . 102. C. caryophyllea. 



g. Perigynia not hairy h. 

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



