46 CYPERACE.\E 



20. Obtusatae. 

 Represented by one species. 70. C. obtusata. 



21. NiTIDAE. 



Represented by one species in our range. 71. C. supina. 



22. Rttpestres. 

 Represented by one species. 72. C. rupestris. 



23. PlRMICTILMES. 



Represented by one species in our range. 73. C. Geyeri. 



24. FiLIFOLIAE. 



Leaf-blades filiform at base, 0.25-0.5 mm. wide; culms filiform, obtusely triangular, 

 smoothish; lowest scale rarely awned. 

 PerigjTiia sharply triangular below, obpyramidal ; basal sheaths rarely Olamentose, 



74. C. elynoides. 

 Perigynla rounded on the angles, obovoid to globose; basal sheaths fllamentose. 



75. C. fiUfoUa. 

 Leaf-blades flattened at base, 1.5-2 mm. wide; culms stoutish, sharply triangular, often 



much roughened; lowest scale conspicuously awned. 76. C. oreocharis. 



25. SCIRPINAE. 



Culms phyllopodic, the culm-leaves 6-10; scales concealing perigynla. 



77. C. pseudoscirpoiclen. 

 Culms aphyUopodic, the culm-leaves 3-6; scales shorter than perigjTiia. 



Perigynla lanceolate, flattish, 4 mm. long. 78. C. sienochlaena. 



Perigynla broader, triangular, 3 mm. long or less. 



Scales very minutely hyaline-margined; perigynia whitish-pubescent. 



79. C. scirpoidea. 

 Scales very broadly hyaUne-margined ; perigj-nia yellowish-hirsute. 



80. C. scirpiformis. 



' 26. AIONTAXAE. 



Basal spikes absent. 



Long stoloniferous ; scales about equalling the perigynia. 81. C. heliophila. 



Without long stolons; scales much shorter than the perigjTiia. 82. C. Peckii. 

 Basal spikes present. 



Lower bract ccceeded by the culm, scale-like, hyaline-margined at base. 



83. C. umbcllala. 

 Lower bract normally exceeding the culm, leaf-like, not hyaline-margined at base. 



Perigynia 2.75 mm. long or less, shallowly bidentate; rootstocks slender. 



84. C. deiiexa. 

 Perigynia longer, deeply bidentate; culms densely cespitose. 



85. C. Rossii. 

 27. DiGiTAT.u;. 



Basal spikes present; scales abruptly cuspidate. 86. C. pedunculala. 



Basal spikes absent; scales not abruptly cuspidate. 



Staminate spike 3-6 mm. long; scales obtuse, one-half as long as the perigynia. 



87. C. concinna. 

 Staminate spike 8-22 mm. long; scales acute to acuminate, from little shorter than 

 to exceeding the perigjTiia. 

 Perigynia loosely pubescent, wider and longer than the scales; staminate spike 



nearly sessile; pistillate spikes few-flowered. 88. C. concinnoides. 



Perigynia appressed-pubescent, narrower and shorter than the scales; staminate 

 spike noticeably peduncled; pistillate spikes many-flowered. 



89. C. Richardsonii. 

 28. Albae. 

 Represented by one species in our range. 90. C. eburnea. 



29. Bicolores. 



Mature perigynia whitish, ellipsoid, not fleshy or translucent. 91. C. Hassei. 

 Mature perigynia orange or brownish, broader, fleshy, translucent. 



92. C. aurea. 



30. Panice.\e. 

 Beak of the perigjTiia none or very short. 



Sheaths of the bracts short; plant glaucous; leaf-blades involute; spikes approximate. 



93. C. livida. 

 Sheaths of the bracts long; plant not glaucous; leaf-blades flat; spikes distant. 



Fertile culm-blades 3-5, 2-3.5 mm. wide; perigj-nia 3.5 mm. long or less; spikes 

 linear. 94. C. tetanica. 



Fertile culm-blades 6-10, 3-7 mm. wide; perigjTiia longer; spikes oblong or linear- 

 oblong. 95. C. Meadii. 

 Beak of the perigj-nia straight, prominent. 96. C. raginala. 



31. L.yxiflorae. 



Represented bj' one species in our range. 97. C. blanda. 



32. GRANUL.ARES. 



Plants cespitose; bracts elongate, overtopping the spikes; staminate spike short-stalked. 



98. C. Shrivcri. 

 Plants with long-creeping rootstocks; bracts short, rarely overtopping the spikes; stam- 

 inate spike long-stalked. 99. C. Crawei. 



