74 FLOBA OF PHILADELPRIA. 



18. GRISEAJfi. 



Leaves slightly glaucous or not at all. 



Pistillate spikes dense, usually many-flowered; leaves 4-6 niui. wide, 



spreading, soft. 49. C. grisea. 



Pistillate spikes loosely several-flowered; leaves 2-4 mm. wide, mostly 

 erect and rigid. 50. C. ami~>hibola. 



Plant very glaucous all over. 51. C. glaucodea^ 



19. GRANULARES. 



Perigynia 2-3 mm. long. 52. C. granulans. 



Perigynia 1-1.5 mm. long. 53. C. Shriveri. 



20. EXTENSAE. 



21. PALLESCENTE8. 



22. OLIGOCARPAE. 



54. C. flava. 



55. C. paUescens. 



Sheaths glabrous. '] 



Perigynia narrowed at both ends, beakless. 56. C. conoidea. 



Perigynia with a short entire beak. 57. C. oligocarpa. 



Sheaths pubescent. 58. C. Hitchcockiana. 



23. LAXIFLORAE. 



Plants not at all glaucous, or very slightly so. \ 



Beak of the perigynium straight, slender. 59. C. polymorpha. 



Beak of the perigynium bent, short or none. 

 Leaves mostly narrow, 2-12 mm. wide. 

 Scales, at least the upper, obtuse. 



Bracts elongated; spikes loosely flowered; culms slender.. 



60. C. tetanica. 

 Bracts short; spikes densely flowered; culms stout. 



61. C. Meadii. 

 Scales acute, cuspidate, acuminate, or awned. 



Perigynia obtusely 3-angled. 



Perigynia obovoid, 2.5-3 mm. long. 



62. C. laxiflora. 

 Perigynia oblong, narrow, about 4 mm. long. 



Perigynia narrowly oblong, 4-5 mm. long, the 



beak oblique. 63. C. styloflexa. 



Perigynia elliptic, 3-4 mm. long, the beak nearly 

 straight. 64. C. striatiila. 



Perigynia sharply 3-angled. 65. C. digitalis. 



Leaves broad, 12-36 mm. wide. 



Bracts leafy, the upper usually overtopping the spikes. 



66. C. Alhursina. 

 Bracts mostly reduced to purple, leafless sheaths. 



67. C. plantaginea. 

 Plants distinctly glaucous. 



Pistillate spikes drooping on hair-like stalks. 68. C. laxiculmis. 

 Pistillate spikes erect. 



Basal leaves much longer than the culm. 69. C. ptychocarpa. 

 Basal leaves shorter than the culm or equalling it. 



Leaves 12-25 mm. wide. 70. C. platyphylla. 



Leaves 2-4 mm. wide. 71. C. livida. 



24. DIGITATAE. 



72. C. setifolia. 



