C5 I'KRACEAE 



181 



Body of pcrigynia globose; pistillate flowers usually 2-3. 



12. Polytrichoideae, represented only by 



13. Pauciflorae, represented only by 



14. Mitratae, represented only by 



15. MONTANAE. 



None of the culms short and hidden among the bases of the 

 leaves. 

 Aphyllopodic and not stoloniferous; lower sheaths little 



fibrillose. 

 Phyllopodic and often long stoloniferous. 



Staminate spike stout; lower sheaths usually long 

 fibrillose. 

 Long stoloniferous; staminate spike 12-25 mm. 



long. 

 Short stoloniferous; staminate spike 4-12 mm. 

 long. 

 Staminate spike not over 1 mm. thick; sheaths little 

 fibrillose. 

 Many of the culms short and hidden among the bases of the 

 leaves. 

 Pistillate and staminate spikes contiguous; culms 



aphyllopodic. 

 Lower pistillate spikes widely separate; culms phyllo- 

 podic. 

 Perigynia 4 mm. long or less, puberulent; leaves 

 slender. 

 Perigynia 2.5-3 mm. long, the beak less than 

 half length of body; achenes brownish, shining, 

 minutely pitted, orbicular obovoid. 

 Perigynia longer, the beak more than half length 

 of body; achenes grayish black, dull, rough- 

 ened, oblong obovoid. 

 Perigynia longer, glabrous, except the long beak; 

 leaves stiff. 



16. Triquetrae, represented only by 



17. Pedunculatae, represented only by 

 IS. Albae, represented only by 



19. Bicolores, represented only by 



20. Paniceae. 



Perigynia beak none or very short, often bent. 

 Leaves 2 mm. wide or less, involute or folded. 

 Leaves 2-6 mm. wide, flat. 



Perigynia turgid; peduncle of staminate spike smooth. 

 Perigynia not turgid; peduncle of staminate spike 

 rough. 

 Fertile culm blades usually 6-10, 3-7 mm. wide; 



perigynia more than 3 mm. long. 

 Fertile culm blades usually 3-5, 2-3 mm. wide; 

 perigynia less than 3 mm. long. 

 Perigynia beak straight, prominent, )i~ l 2 length of body. 



51. C. Jamesii. 



52. C. kptalea. 



53. C. panciflora. 



54. C. caryophyllca. 



55. C. communis. 



56. C. pennsylvanica. 



57. C. varia. 



5S. C. novae-angliae. 



59. C. nigromarginata. 



60. C. abdita. 



61. C. umbellata. 



62. C. tonsa. 



63. C. hirti folia. 



64. C. pedunculata. 



65. C. eburnea. 



66. C. aurea. 



67. C. livida. 



68. C. panicea. 



69. C. Meadii. 



70. C. tetanica. 



71. C. polymorphs. 



