116 CYPERACEAE 



Beak of the perig>Tiia smooth or very nearly so; scales obtuse to acutlsh. 



strongly tinged with reddish brown or chestnut; spikes closely ap- 

 proximate. 



Terminal spike strongly tapering at base; culms rough at apex only. 



62. C. Lachenalii. 

 Terminal spike little tapering at the base; culms usually very rough. 



63. C. Heleonastes, 

 Beak of the perig.\Tiia serrulate, or if smooth scales acutish to cuspidate and 



scarcely, if at all, tinged with reddish brown ; lower spikes remote. 

 Plant glaucous ; leaf-blades 2-4 mm. wide ; spikes many-flowered ; 

 perigynia scarcely beaked, appressed ascending, with emarginate or 

 entire orifice. - 64, C. canescens. 



Plant not glaucous; leaf-blades 1-2.5 mm. wide; spikes fewer-flowered; 

 perigynia distinctly beaked, loosely spreading, with minutely biden- 

 . . tate orifice. 65. C. brunnescens, 



Perig>-nia ovate, broadest near the base; beak conspicuous, strongly serrulate. 



66. C. arcta. 



18. PlIYLLOSTACHYAE. 



PerigjTiia with long smooth beak ; foliage deep green. 67. C. durifnlia, 



Perig>Tua with short sparingly serrulate beak; foliage light or glaucous green. 



68. C saximonlana. 



^ , , 19. POLyXRTCnOIDEAE. 



Kepresented by one species. 69. c. leptalea. 



-, ^ ^ 20. OliXUSATAE. 



Kepresented by one species. 70. C. obtusaia. 



21. NiTIDVE, 



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



^ , , 22. RUPESTRES. 



Represented by one species. 72. C. rupeslris. 



23. FlUMICULMEJS. 



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, 



smoothLsh; lowest scale rarelv awned. 

 PerigjTiia sharply triangular below, obpyramidal ; basal sheaths rarely filamentose. 



-D • ■ J J , 74. C. elynoides. 



Perigynia rounded on the angles, obovoid to globose; basal sheaths filamentose. 



T^ruij «.. ,^, 75. C. filifolia. 



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

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



Culms 



25. SCIRPINAE. 



-^ , I. 1, J. ,, , , 77. C. pseudoscirpoidea 



Culms aphyllopodic, the culm-leaves 3-6; scales shorter than perigynia 



Perigynia lanceolate, flattish, 4 mm. long. *^ 78. C. slenochlaena, 



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



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



Scales very broadly hyaline-margined; perigynia yellowish-hirsute. 



80. C. scirpiformis. 



T, , ,, • ^ 26. MONTANAE. 



Basal spikes absent. 



L^ng stoloniferous ; scales about equalling the perigynia. 81. C. heliophila. 



Without long stolons; scales much shorter than the perigynia. 



Basal spikes present. ^^' ^' ^^^^^^' 



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



^^'^^J.w;^ normally exceeding the culm, leaf-like, not hyaline-'mai^ned a^t base. 

 PerigyTiia 2.7o mm. long or less, shaliowly bidentate; rootstocks slender. 



Perigynia longer, deeply bidentate; culms densely cespitose*' ' ''^^"'^"• 



85. C Rossii. 

 27. DicaXATAE. 



Basal spikes present; scales abruptly cuspidate. 86 C vedunculata. ' 



Basal spikes absent; scales not abruptly cuspidate peauncuuin 



Stammate spike 3-6 mm. long; scales obtuse, one-half as long as the perigjTiia. 



Staminate spike 8-22 mm. long; scales acute to acuminate, from iittle^shorter thar 



to exceeding the peng\-Tua. 

 Perigy-nia loosely pubescent, wider and longer than the scales; ataminate spike 

 ■o^J^ --^ sessile; pistillate spikes few-flowered. 88. C. concinnoides. 



i-erigyTiia appre^ed-pubescent, narrower and shorter than the scales; staminat* 

 spike noticeably peduncled; pistiUate spikes many-flowered. 



89. C. Richardsonii. 



