48 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Second glume similar to the 



first, not broadened 



upward. 



Panicles narrow, dense 



and spikelike, 



the branches 



erect 60. Koeleria (p. 92). 



Panicles open, the 

 branches spread- 

 ing 61. Eragrostis (p. 93), 



Lemmas 5 to many-nerved. 



Spikelets with 2 or more of the up- 

 per glumes empty, broad and 



infolding each other 62. Melica (p. 95). 



Spikelets with the upper glumes 

 flower-bearing or narrow and 

 abortive. 

 Stigmas plainly arising from be- 

 low the apex of the ovary. . .63. Bromus (p. 95). 

 Stigmas placed at or near the 

 apex of the ovary. 

 Spikelets in 1-sided fascicles 

 arranged in a glomerate or 



interrupted panicle 64. Dactylis (p. 97). 



SjDikelets in panicles of ra- 

 cemes. 

 Glumes more or less laterally 

 compressed and keeled. 

 Flowers dioecious; lemmas 



coriaceous 65. Distichlis (p. 98). 



Flowers monoecious, most 

 of the flowers perfect; 

 lemmas thin, scari- 



ous- margined 66. Poa (p. 98). 



Glumes rounded on the back, 

 at least below the mid- 

 dle. 

 ■ Lemmas acute, pointed or 



awned at the apex. . .67. Festuca (p. 101). 

 Lemmas obtuse or acutish, 

 usually toothed. 

 Lemmas distinctly 5 to 

 7-nerved; styles 



present 68. Panicularia (p. 103). 



Lemmas obsciirely 5- 

 nerved; styles 

 none 69. Puccinellia (p. 104). 



Tribe X. HORDEAE. 



Spikelets usually single at the nodes of the rachis. 



Glumeswith their sides tiu'ned toward the rachis. .70. Agropyron (p. 104). 

 Glumes with their backs turned toward the rachis. 71. Lolium (p. 106). 



