CYPBRACEAE (SEDGE FAMILY) 



211 



the perigynia. 

 Scales rough-awned ; coarse' southern plant . 

 Scales blunt ; slender northern plants. 

 Spikes sessile, 



148. C. verrucosa. 



closely approximate in an irregular head 78. C, 

 Spikes mostly peduncled, spreading or drooping . . 79. C. 

 ding the perigvnia. 



Halleri. 

 atrata, v. ovata. 



V. Scales much exceeding the perigynia. 



Spikes sessile, erect 80. C. polygama. 



Spikes peduncled, spreading or drooping . . . 111. C. paupercula. 

 U. Scales white or greenish, or if very brownish the spikes 



linear-cylindric W. 

 . W. Spikes mostly sessile or subsessile and erect X. 



X. Spikes mostly remote ; leaves glabrous, short and broad 



(4-10 mm. broad) 135. C. granularis. 



X. Spikes approximate or overlapping ; leaves long and 

 slender (1-1 mm. broad), at least the sheaths hairy. 

 Perigynia smooth, or when young slightly hairy. 



Leaves smooth (81) C. triceps, v. Smithii. 



Leaves hairy 81. C. triceps, v. hirsuta. 



Perigynia very hairy. 

 Terminal spike (including the staminate base) 1.8-4 



cm. long, one tenth to one seventh as thick . 82. C. virescens. 

 Terminal spike 9-18 mm. long, one fifth to one 



third as thick (82) C. virescens, v. Swanii. 



W. Spikes mostly peduncled, spreading or drooping Y. 

 Y. Perigynia 2 mm. or more thick. 



Scales blunt or cuspidate, much shorter than the 



perigynia i . 



Scales lorig-awned, usually equaling the perigynia . 

 Y. Perigynia less than 2 mm. thick Z. 



Z. Bracts with distinct long sheaths ; perigynia bluntly 



angled a. 

 a. Perigynia rounded or narrowed but not definitely 



stipitate at base b. 



b. Perigynia less than 4 mm. long, beakless. 

 Sheaths glabrous ; perigynia obtuse . 

 Sheaths pubescent ; perigynia acutish 

 b. Perigynia 4 rum. or more long. 



Leaves hairy ; perigynia beakless 

 Leaves smooth ; perigynia beaked. 

 Scales white or whitish ; perigynia with long 

 conic-cylindric beaks .... 

 Scales with dark-brown margins ; perigynia 

 with short-conic beaks .... 

 a. Perigynia with slender stipitate bases . 

 Z. Bracts sheathless ; perigynia sharply angled 

 T. Perigynia wide-spreading or reflexed. 



Perigynia orbicular to broadly elliptic, compressed, nerve- 

 less, with tiny short point ; bracts erect 

 Perigynia terete, beaked , strong-ribbed ; bracts divergent. 

 Beak about as long as body of perigynium. 

 Beak much shorter than body of perigynium . 

 Q. Terminal spike staminate throughout c. 



c. Lowest foliaceous bracts of the inflorescence sheathless, or with 

 short colored sheaths or colored auricles, sometimes wanting 

 or reduced to mere colored sheaths d. 

 d. Perigynia pubescent (if rarely glabrous, the spikes mostly 



crowded at the base of the densely tufted leaves) e. 

 e. Spikes subtended by colored tubular sheaths which are 



without green blades. 

 Pistillate spikes cylindric, 1-2 cm. long ; scales exceeding 



the perigynia 120. C. Richardsoni. 



Pistillate spikes subglobose, 4-7 mm. long; scales much 



shorter than the perigynia 119. C. concinna. 



e. Spikes bractless or the lowermost with green foliaceous bracts /. 



/. Leaves and culms soft-pubescent 101. C. pubescens. 



f. Leaves and culms glabrous g. 



g. Leaves mostly basal, the culms naked or with short 



reduced leaves h. 



h. Scales rough-cuspidate ; perigynia yellowish-brown . 102. C. caryophyllea. 

 h. Scales smooth ; perigynia green or whitish i. 



i. Plant strongly stoloniferous, the elongate often leaf- 

 less stolons scaly-bracted and creeping. 

 Beak one fourth to one fifth as long as the body of 



. the perigynium 100. C. pennsylvanica. 



Beak about as long as the body . (100) C. pennsylvanica, v. lucorum. 

 i. Plant caespitose or slightly stoloniferous, the basal 



leafy shoots strongly assurgent j. 



j. Some (or all) of the culms short and more or less 

 hidden by the bases of the leaves k. 



88. C. formosa. 

 84. C. Davisii. 



85. C. gracillima. 



86. C. aestivalis. 



87. C. owylepis. 



146. C. debilis, vars. 



147. C. renusta, v. minor. 

 145. C. arctata. 



115. C. prasina. 



88. C.Shortiana. 



138. C.flava. 



139. C. Oederi. 



