574 Bulletin No. 205 [March, 



1. Lemmas firm, somewhat hard- 

 ened, faintly many-nerved, 

 acuminate, 

 m. Lower florets empty but 

 like the upper in appear- 

 ance ; spikelets strongly 

 riattencti ; lemmas not pol- 

 ished ; panicle drooping. 

 52. Vniola 

 mm. Lower florets perfect; 

 spikelets not flattened, 

 florets turgid, polished; 

 grain at maturity beaked, 

 expanding the lemma and 

 palea. 51. Diarina 



11. Lemmas herbaceous, 5- to 9- 

 nerved, the nerves usually 

 strong. 

 • m. Spikelets strongly flat- 



tened, densely crowded 

 in 1-sided clusters at the 

 ends of the stiff, naked 

 panicle branches. 



53. Dactylis 

 . mm. Spikelets not flattened, nor 

 in 1-sided clusters. 

 n. Lemmas keeled, and 

 usually with a tuft 

 of cobwebby, white 

 hairs at base (blue- 

 grass). 54. Poa 

 nn. Lemmas not keeled, 

 rounded on the back, 

 not coh^'ehby at bate. 

 0. Lemmas obtuse, us- 

 ually scarious at 

 the tip ; nerves 

 parallel, usually 

 prominent. 

 55. Panicularia 

 00. Lemmas acute or 

 awned; nerves 

 approrching at 

 the apex. 

 p. Lemmas not 

 t t h e d , 

 awned from 

 the tip or 

 a w nl es s; 

 spikelets not 

 over 15 mm. 

 long, usually 

 less. 



56. Festuca 

 pp. Lemmas m i - 



nu t el y 2- 

 toothed, us- 

 ually awned 

 from just 

 below the 

 apex; spike- 

 lets rarely 

 less than 2 

 cm. long. 



57. Bromiis 



