210 



CYPERACEAE (SEDGE FAMILY) 



Pistillate spikes 5-8 mm. thick . . (66) <'. aquatilix, v. elatior. 



Scales cuspidate (66) C. aqvattUt. v. cuxphlata. 



Scales hidden by the perigynia . . . ((56) C. aquatilis, v. virescen*. 

 I. Culms low ; leaves mostly basal, smooth ; basal off- 

 shoots chiefly repent 67. C. rigida. 



II. Perigj nia elongate, with an empty twisted tip . . 68. C. torta. 

 G. Perigynia nerved. 



Caespitose, not stoloniferous ; green central portion 



of the scale about as broad as the darker margins . 69. C. lenticularis. 

 Stoloniferous ; green midrib of the purple or blackish 



scale very slender 70. C. Goodenotcii. 



F. Culms numerous in stools ; lower sheaths fibrillose. 



Perigynia elliptic, tapering about eoually to base and apex. 

 Pistillate spikes dense, mostly full at base ; scales blunt, 

 slightly if at all exceeding the perigynia. 



Pistillate spikes 2-7 cm. long 71. C. strict,!. 



Pistillate spikes 0.5-1. 5 cm. long . . . . (71) C. ttricta, \. cnrtixxhna. 

 Pistillate spikes rather loose, long-attenuate at base ; 



scales acutish (71) (7. stricta, v. aiKjnutnta. 



Perigynia obovate or orbicular, shorter than the attenuate 



scales (71) C. stricta, v. decora. 



E. Perigynia plump, subterete. 



Mature perigynia fleshy, pyriform or subglobose, orange or 



brownish, glabrous 72. C. aurea. 



Mature perigynia not fleshy, ellipsoid, slender-stipitate, 



white, pulverulent 73. C. bicolcr. 



B. Perigynia lustrous. 

 Perigynia nerved. 



Leaves flat; bracts ascending 180. C. Grahami. 



Leaves soon involute ; bracts divergent 181. (\rotundata. 



Perigynia nerveless. 



Leaves flat; pistillate spikes subglobose or short-cylindric, 



5-8 mm. thick 179. C. xasatilix. 



Leaves involute or filiform ; pistillate spikes slender, 8-7 mm. 



thick (179) C. saxatilis, v. miliarix. 



A. Achenes trigonous; stigmas 3 (very rarely and exceptionally 2) K. 

 A'. SPIKES SOLITARY, TKKMINAL L. 

 L. Spikes naked or without large leafy bracts M. 



M. Leaves tongue-shaped, 2-4 cm. broad 77. C. Fraseri. 



M. Leaves grass-like, narrow W. 



N. Spikes monoecious, green or straw-color ; perigynia gla- 

 brous O. 



0. Spikes staminate at tip, few-flowered : perigynia with entire 

 tips. 



in a linear-cylindric 



Perigynia appressed-ascending, 

 spike, beakless. 



Perigynia 2.5-3.5 mm. long; achenes lustrous, not 



puncticulate, obtusely trigonous . . . 75. C. leptalea. 



Perigynia 4-5 mm. long ; achenes puncticulate, barely 



lustrous, sharply trigonous ..... 76. (7. Ifarperi. 



Perigynia soon refracted, slender-beaked . . .74. C. paueiflora. 

 O. Spikes staminate at base, many-flowered ; perigynia with 



long bldentate beaks. 



Scales of pistillate flowers subulate-tipped . . . 161. C. aquarrona. 

 Scales blunt ......... 162. C. typhinoides. 



JV. Spikes dioecious, purplish-brown; perigynia pubescent. 



Culms shorter than the leaves ; scales short-aristate, ex- 



ceeding the perigynia ....... 116. 



Culms exceeding the leaves; scales blunt, shorter than 



the perigynia 



L. Spikes subtended by long leafy bracts. 



Perigynia somewhat 2-edged. 



Scales all bracteate, overtopping the perigynia . . ~. 

 Only the lowest scales overtopping the pe'rigynia . 

 Perigynia globose, with slender cylindric beak * . . . 

 A' -MMKKS .' <>i: MI it K /'. 

 /'. I'l'i'liji/nin nnt riijitlli/ hiifftitufi'. ///' orific? entire or emar- 



ginaie,, the teeth &prMHt *<>t't ami t/u'it Q. 

 Q. Ti-niiiii;il spikt- bt'arintr some pistillate flowers JR. 

 It. Terminal spike pistillate throughout, brown or purplish, the 

 lower spike much smaller; porigynia hairy . . . 

 R. Terminal spike with both staminate Mid plsttwWfl tlouci-s N. 

 S. Terminal spike pistillate only at base ; the capillary pt'dun- 

 di-s ofic n basal : jierigynia sharply antrl.-d . . . 

 S. Terminal spike pistillate at'siiintnit, or. if pistillate at base, 



the spikes mostly near the tip of the culm T. 

 T. IVrigvnia ascending U. 



I . -rales brown to purplish-black ; spikes globose, ovoid 

 or thick-cylindric V. 



92. C. tsdrpoidea. 



89. C. BticJcii 



90. C. 



91. C. 



92. C. scirpoidea. 



118. C. pedunculate. 



