208 CYPERACEAE 



17. Scirpinae. 



Represented by one species in our range 65. C. gigas. 



18. Montanae. 



Basal spikes not developed 66. C. iiiops. 



Basal spikes present. 



Perigj'nia finely many-ribbed as well as strongly 2-keeled. 



Scales purplish-tinged, obtuse to cuspidate ; body of perigyniuni globose ; staminate 

 spikes many-flowered; basal pistillate spikes on elongated very slender peduncles. 



67. C. globosa. 

 Scales reddisli-brown tinged, cuspidate or long-awned; body of perigynium oval; stam- 

 inate spikes few-flowered; basal pistillate spikes on short, erect peduncles 



68. C. brainerdii. 

 Perigynia strongly 2-keeled, otherwise nerveless. 



Bract of lowest non-basal pistUlate spike leaflet-like, exceeding eulms, if at all colored, 

 purplisli-brown tinged at base. 



Perigynia 2.5 to 3 mm. long, the beak 0.25 to 0.75 mm., long, shallowly bidentate 



69. C. irevipes. 



Perig\'nia 3 to 4.5 mm. long, the beak 0.75 to 1.50 mm. long, bidentate....70. C. rossii. 



Braet of lowest non-basal pistillate spike squamiform and shorter tlian culm or, if longer, 



auriculate and strongly reddish-brown tinged at base 71. C. brevicaulis. 



19. Digitatae. 



Represented by one species in our range _ 72. C. concinnoides. 



20. Bicolores. 



Perigynia short-tapering at apex, straw-colored, 2.5 to 3.75 mm. long; achenes strongly apicu- 



late - 73. C. salinaef ormis. 



Perig>Tiia rounded or truncate at apex, orange-colored or white-pulveinilent, smaller; achenes 

 minutely apiculate. 

 Mature perigynia whitish, ellipsoidal, not fleshy or translucent, rather obscurely ribbed; 



scales appressed _ - _ 74. C. Iiassei. 



Mature perigynia orange or bro'ivnish, broader, fleshy or translucent, strongly ribbed; scales 

 divaricate at maturity 75. C. aurea. 



21. Paniceae. 



Perigj-nia beakless or nearly so; bract sheaths short; plant glaucous; leaf -blades narrow, 



involute _ _ 76. C. livida. 



Perigynia stronglj' beaked; bract sheaths long; plant not glaucous; leaf -blades broad, flat- 



77. C. calif omica. 



22. Laxiflorae. 



Represented by one species in our range 78. C. hendersonii. 



23. Triquetrae. 



Lowest braet sheathless or very short -sheathing; perigynia glabrous, strongly ribl>ed or nerved. 

 Perigj-nia ovoid, 3.5 to 4.25 mm. long, abruptly short-beaked, the sides several-nerved. 



79. C. fiaccifolia. 

 Perigynia ovoid-lanceolate, 3.75 to 5 mm. long, tapering into the beak, the sides strongly 



ribbed _ 80. C. whitneyi. 



Lowest bract long-slieatliiug ; perigynia hairy, faintly nerved or nerveless. 

 Leaf -blades liairy; spikes oblong or short-oblong, the upper approximate. 



Perigynia 4 to 5 nmi. long, round-tapering at base, finely many-nerved 



81. C. gynodynama. 



Perigynia 3.5 to 4 mm. long, tapering at base, 2-keeled, obscurely striate 



82. C. hirtissima. 

 Leaf -blades not haiiy; pistillate spikes linear, widely separate 83. C. triquetra. 



24. Debiles. 



Represented by one species in our range 84. C mciidooinens-is. 



25. Frigidae. 



Perigynia triangular or slightly flattened, the beak bidentulate; scales obtusish, the midvein 

 not prominent at apex. 

 Spikes widely separate, the staminate one strongly overtopping the uppermost pistillate one; 



perigynia triangular, 3.5 mm. long or less 85. C. Icmnwnii. 



Uppermost pistillate spikes bunched, little exceeded by the staminate one; perigynia com- 

 pressed-triangular, longer. 



PistUlate spikes oblong; scales reddish-brown _ _ 86. C. luzuUna. 



Pistillate spikes linear-oblong; scales dark-tinged _ 87. C. ablata. 



Perigynia strongly flattened, the beak bidentate; scales sharp-pointed with midvein prominent 

 to apex. 

 Perigynia glabrous; scales smooth; bract sheaths strongly enlarged upward; leaf -blades 



very leathery _ 88. C. luzulaefolia. 



Perigynia sparsely hairy; scales more or less hairy; braet sheaths scarcely enlarged upward; 

 leaf-blades not leathery _ _ 89. C. fissuricola. 



