^10 



cymuacjlae (sedge j^amily) 



Pistillate spikes 5-8 mm. thick . (66) C. aqv^atiUa, v. elatior. 



Scales cuspidate (66) C. aquatilis, v. cuapidata. 



Scales hidden by the nerigynia . . . (66) C. aguatilis, v. virescen^. 

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

 shoots chiefly repent .... . 67. C7. rigida. 

 If. Pei-igynia elongate, with an empty twisted tip , .68. C. toria. 

 Q. Perigynia uerved. 



Caespitose, not stoloniferous ; green central portion 



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

 Stoloniferous ; green midrib of the purple or blackish 



scale very slender . 70. f. Goodenowii. 



F. Culms numerous in stools ; lower sheaths fibrillose. 



Perigynia elliptic, tapering about equally 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 ... , 1\, C. slricUi. 



Pistillate spikes 0.5-1.5 cm. long . . . . (71) C «^c/a, v. CMr^ss^ma. 

 Pistillate spikes rather loose, long-attenuate at base ; 



scales acutish (71) C. strictO; v. angutttutit. 



Perigynia obovate or orbicular, shorter than the attenuate 



scales . . (71) C.etricta, y. 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 7S. (7. Mcolor. 



S. Perigynia lustrous. 

 Perigynia nerved. 



Leaves flat ; bracts ascending 180. O. Grahami. 



Leaves soon involute ; bracts divergent 181. C. rotundata. 



Perigynia nerveless. 



Leaves flat ; pistillate spikes subglobose or short-cylindric, 



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



Leaves involute or^fiUform ; pistillate spikes slender, 8-7 ram. 



thick (179) C, saxaUlis, v. miliaris 



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

 K. Spikes solitary, terminal L, 

 L. Spikes naked or without large leafy bracts M. 



M. Leaves tongue-shaped, 2-4 cm. broad 11. C-. Fraseri. 



M. Leaves grass-like, narrow K. 

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

 brous O. 

 O. spikes staminate at tip, few-flowered ; perigynia with entire 

 tips. 

 Perigynia appressed-ascending, in a linear-cylindric 

 spike, beakless. 

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



puncticulate, obtusely trigonous . . . . 75. C. teptalea. 

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



lustrous, sharply trigonous .... 76. C. Uarperi. 



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

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

 long bidentate beaks. 

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



Scales blunt 162. C. iyphinoides. 



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



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

 ceeding the perigynia 116, C. picta. 



Culms exceeding the leaves; scales blunt, shorter than 



the perigynia 92. C. ecirpoidea. 



L, Spikes subtended by long leafy bracts. 

 Perigynia somewhat 2-edged. 

 Scales all bracteate, overtopping the perigynia . . . 89. <?. Jiackii. 

 Only the lowest scales overtopping the perigynia . . 90. C. Willdenoicii. 

 Perigynia globose, with slender cylindric beak . . ,91. C. Jamesii. 

 K. Spikes 2 or more P. 



P. Perigynia not rigidly 'bidentate, the orifice entire or emar- 

 ginnte, the teeth if present soft and ihin Q. 

 Q. Terminal spike bearing some pistillate flowers R. 

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



lower spike much smaller ; perigynia hairy . . , 92- C adrpoidea. 

 R. Terminal spike with both staminate and pistillate flowers S. 

 S. Terminal spike pistillate only at base ; the capillary pedun- 

 cles often basal ; perigynia sharply angled . . _ . 118. 0, pedunculata. 

 S. Terminal sinke pistillate at summit, or^ if pistillate at base, 

 the spikes mostly near the tip of the culm T. 

 T. Perigynia ascending U. 

 U- Scales brown to purplish-black ; spikes globose, ovoid 

 or tUlck-cylindrlc V. 



