CYPERACEAE (SEDGE FAMILY) 



213 



Spikes all sessile and approximate ; perigyuia obovoid, 

 prominently ribbed, retuse, with a distinct short 



entire beak 109. G. dbhrmiata. 



Lowest spike peduncled; perigynia narrowly obovoid, 

 faintly nerved or nerveless, narrowed to tho beakless 



tip 110 C. palleseens. 



q. Perigynia distinctly beaked w. 

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

 oblique ; the bracts very long and much exceeding the 

 inflorescence, rarely 5 mui. broad. 



Leaves Involute 187. C. exiensa. 



Leaves flat. 

 Beak about equaling body of perlgynium .... 18S. C.^flava. 

 Beak much shorter than body of p'erigynium . . . 189. C. Oederi. 

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

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

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

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

 spreading y. 

 y. Leaves soft, ribbon-like, dark gi'een ; lower bract 5-10 



ram. wide, much exceeding the inflorescence . . 150. C, scabraia. 

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

 equaling the inflorescence. 

 Perigyuia spreading-ascending, glaucous, faintly-nerved 



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

 Perigynia squarrose, deep green or brownish, strongly 



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



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

 nerveless or slightly nerved; spikos loosely flowered, 

 the thin lustrouR perigynia stronglj' ascending &. 

 z. Perigynia abruptly contracted to an awl-shaped beak 



as long as the body . 141. C. longirostris. 



a. Perigynia gradually contracted to the beak. 



Leaves pubescent ; pistillate spikes 5-S mm. thick . 143. C. casianea. 

 Leaves glabrous ; pistillate spikes 2-4 mm. thick . , 144. 0. capillaria. 

 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. 

 6, 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. O. asBinitoinenms. 



Perigynia smooth, approximate 141, 0. longwostris. 



V. Perigynia gradually contracted to the beak d. 

 d. l*istillate spikes oblong-cylindric, densely flowered. 

 Spikes 5-10 mm. thick. 



Leaves glabrous ; scales white 142. C. clierokeensis. 



Leaves pubescent ; scales brown 148. G. castanea. 



Spikes 2-4 mm. thick. 

 Plant 0.6-1.5 dm. high ; spikes approximate . , . 144. O. capillaris. 

 Plant taller; spikes remote . " . . . (144) G. capillaris, v. elo7igata 

 d. Pistillate spikes linear-cylindric e. 



e. Basal sheaths reddish-purple or castaneous /. 

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

 gynia stipitate, ovoid-trigonous .... 145. O. arctata. 

 f. Basal leaves S-7 ram. 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 146. G. dehilis. 



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) G. deiilis, v. Rudffei, 



Perigynia one third longer than the scales; leaves 



4-6 mm. wide (146) G. debilie, v. strietior. 



Perigynia alternate and mostly remote, not over- 

 lapping (146) G. deMHs.Y. inierjecta 



Perigynia hairy (146) G. debiiis, v. puberu 



e. Basal sheaths duU pale brown .... (127) G. la^fiora, v. lepton&rvia 

 h. Plant loosely stoloniferous, the elongate rootstock slender ; 

 perigynia beakless or with short or abrupt beak g. 



g. Perigynia hairy 102. (7. caryophylUa. 



g. Perigynia not hairy h. 

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



