210 



CYPERACEAE (SEDGE FAMILY^ 



C. rigida. 

 C. iorta. 



C. lenticularia. 

 C. Goodenowii. 



71. C. siricta. 

 C. stricta, v. eurtissima. 



anguntuta. 



Pistillate spikes 5-8 mm. thick . . (66) 0. aquatilis, v. elatior 



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



Scales hidden by the perigynia . . . (66) C. aquatilis, v. virescen-s. 

 J. Calms low; leaves mostly basal, smooth; basal off- 

 shoots chiefly repent 67. 



M. Perigyuia elongate, with an empty twisted tip . . 68. 

 O, Perigynia nerved. 



Caespitose, not stoloniferous ; green central portion 



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

 Stoloniferous ; green midrib of the purple or blackish 



scale very slender 70, 



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 



Pistillate spikes 0.5-1.5 cm. long . . . . (71) 

 Pistillate spikes rather loose, long-attenuate at base ; 



scales acutish (71) C. str%cta 



Perigynia obovate or orbicular, shorter than the attenuate 



scales C^l) C. stricta, v. decjra. 



E. Perigynia plump, subterete. 



Mature perigynia lleshv, pyriform or subglobose, orange or 



brownish, glabrous 72. C awrm. 



Mature perigynia not fleshy, ellipsoid, slender-stipitate, 



white, pulverulent 78. <7. hieolor. 



B. Perigynia lustrous. 



Perigynia nerved. ..„„ x> ^ x i 



Leaves flat ; bracts ascending 180. C. Grahami. 



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



Perigynia nerveless. 



Leaves flat; pistillate spikes subglobose or short-cylindric, 



5-8 ram. thick 179. C. saxattlis. 



Leaves involute or filiform ; pistillate spikes slender, £-? mm. .,. . 



tjiick (I'f9) C- saxahlts, v. mihans 



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 



M. Leaves grass-like, narrow N. 

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

 brous 0. 

 0. 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 .... 

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

 lustrous, sharply trigonous .... 

 Perigynia soon refracted, slender-beaked 

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

 long bidentate beaks. 

 Scales of pistillate flowers subulate-tipped 



Scales blunt 



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



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

 ceeding the perigynia 



Culms exceeding the leaves; scales blunt, shorter than 



the perigynia 



Z. Spikes subtended by long leafy bracts. 

 Perigynia somewhat 2-edged. 

 Scales all bracteate, overtopping the perigynia 

 Only the lowest scales overtopping the perigynia 

 Perigynia globose, with slender cylindric beak 

 K. Spikes 2 or more P. 

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

 ginnle, the teeth if present soft and thin Q. 

 Q. Terminal spike bearing some pistillate flowers R. 

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



lower spike much smaller; perigynia hairy . . . 9'i. C. sctrpoidea. 

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

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



cles often basal ; perigynia sharply angled . . . 118. C. peduncuJuta, 

 8. Terminal spike 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 thick-cyllndrlc V, 



77. C, Fraaeri. 



75. C. teptalea. 



76. C. Harperi. 

 74. C.paudjlora. 



161. C. squarrosa. 



162. 0. typhinoidea. 



116. 

 92. 



C. picta. 



C. scirpoidea. 



C. BacJcii. 



C. Willdenoicii, 



C. Jamesii, 



