SEDGE FAMILY 45 



Pjri2;vnia ovate-lanceolate or broxder, at most twice as long as wide. 

 Pcirigynia narrowly to broadly ovate. 3-4 mm. long. 



Perigynia brownish; spikes closely aggregate, rounded at base. 



44. C. Bebbii. 

 Perigynia green; spikes contiguous to widely separate, usually tapering 



Leaf-blades 2.5 mm. wide or less; perigynia spreading-ascending; 



culms slender. 45. C. tenera. 



Leaf-blades 2-6 mm. wide (averaging 4 ram.); perigynia appressed- 

 ascending; culms stout. 46. C. tincla. 



Pori.!vnia ovate or broader, 3.75-6 mm. long. 



Pe.igynia thick, abruptly short-beaked; scales little, if at all, tinged 



with brownish red. 47. C. brevior. 



Perigynia tliin, tapering to the beak; scales strongly tmged with chest- 

 mit-brown. 48. C. Eggleslonii. 



Beak of the perigynia slender, terete and scarcely, if at all, serrulate towards tip, 

 obliquely cut, at times becoming obscurely bidentate. 

 Scales about the length of the perigynia, and of nearly the same width above, the 

 perigynia nearly entirely concealed. 

 Culms and head stiff and rigid. 



Culms 1-3 dm. high, in large stools; scales strongly tinged with reddish 



brown; perigynia lanceolate. 49. C. phaeocephala. 



Culms taller, not in large stools; scales lighter-colored; perigynia ovate, 

 in age golden yellow at base. 50. C. xerantica. 



Culms slender; head flexuous or moniliform. 



Scales light reddish brown tinged. 51. C. practicola. 



Scales chestnut-brown tinged. 52. C. Piperi. 



Scales shorter than perigynia and noticeably narrower above, the upper part of 

 perigynia largely exposed. 

 Perigynia thin and membranous, except where distended by the achene. 

 Perigynia 3.5-5 mm. long; culms slender. 



Perigynia lance-ovate, very narrowly margined, spreading; culms 



biennial. 53. C. microptera. 



Perigynia ovate, strongly margined, appressed; culms annual. 



54. C. festivella. 

 Perigynia 4.5-6 mm. long; culms low. 



Perigynia lanceolate to broadly ovate, nerveless or nearly so on inner 

 face, the beaks conspicuous; culms slender, ascending or decumbent. 



55. C. nubicola. 

 Perigynia narrowly lanceolate, finely nerved on inner face, the beaks 



appressed; culms stiff, erect. 56. C. ebenea. 



Perigynia strongly plano-convex, the walls thick. 



Spikes densely capitate; beak of the perigynia obliquely cut, dark-tipped. 



57. C. pnchystachr/a. 

 Spikes not capitate; beak of the perigynia bidentate, reddish-tipped. 



58. C. Preslii. 



17. Canescentks. 

 Spikes androgynous; perigynia unequally biconvex. 59. C. disperma. 



Spikes gynaecandrous; perigynia plano-convex. 



Lowest bract bristle-like, much prolonged, many times e.xceeding its 1-5-flowered 



spike; spikes widely separate. 60. C. trisperma. 



Lowest bract much shorter or none; spikes several-many-fiowered, the upper approxi- 

 mate. 

 Spikes 2-4, subglobose. closely approximate, forming an ovate or subglobose head; 



perigynia scarcely beaked; scales white-hyaline. 61. C. trnuiflora. 

 Spikes one-many, the lower more or less strongly separate; head elongate; peri- 

 gynia shortly to strongly beaked; scales darker. 

 Perigynia broadest near middle; beak short, smooth or moderately serrulate. 

 Beak of the perigynia smooth or very nearly so; scales obtuse to acutish, 

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

 proximate. 

 Terniinal 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. Heleonasles. 

 Beak of the perigynia 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. 

 Perigynia ovate, broadest near the base; beak conspicuous, strongly serrulate. 



66. C. arcta. 

 18. Phyllost.-vchyae. 

 Perigynia with long smooth beak; foliage deep green. 67. C. durifolia. 



Perigynia with short sparingly serrulate beak; foliage light or glaucous green. 



68. C. saxirnonlana. 



19. POLYTRICHOIDE.^E. 



Represented by one peciess. 69. C. leptalea. 



