no CHLORIDEAE 



eat it fairly well, but when the seeds ripen the spikelets become 

 very sharji pointed and probably hurt the animals' mouths. 



3. BoutelOUa vestita (S. Wats.) Scribn. An annual of 

 little importance on the sandy mesas of the southern part of the 

 State; in the T^ower Sonoran Zone. 



4. Bouteloua polystachya Torr. Another Six-weeks 



Grama., associated with number 2; in the Lower Sonoran Zone. 



5. Bouteloua eripoda Torr. Black Grama. Woolly foot. 

 The commonest and most important range grass of the southern 

 part of the State on the mesas: in the Lower Sonoran Zone, but 

 often occurring sparingly in the Upper Sonoran. This grass spreads 

 slowly by runners and where heavily grazed it probably spreads 

 hardly at all. 



6. Bouteloua brevlseta Vasey. A characteristic grass of 

 the gA-psum deposits in the southern and southeastern part of the 

 State; in the Lower Sonoran Zone. 



7. Bouteloua hirsuta Lag. Hairy Grama. Black Grama. 



Common on the lower mountains and higher mesas of the southern 

 part of the State; in the Upper Sonoran Zone and extending into 

 the Lower Sonoran. 



8. Bouteloua oligostachya Torr. Blue Grama. White 



Grama, t'ominon on the upper plains and in the mountains nearly 

 throughout the State; in the Upper Sonoran and Transition Zones. 



49. LEPTOCHLOA Beauv. 



Spikes very slender, 1 mm. broad or less; 



spikelets small, 2- to 4-flowered, scattered. 1. L. mucronata. 

 Spikes mucii stouter; spikelets generally with 

 sevei'al flowers, and crowded. 

 IMant annual, much branched from the 



base; flowering glumes short awned. 2. L. fascicularis. 



Plants perennial; flowering glumes awnless. 

 Panicle elongated and narrow: spikes all 



ascending; flowering glume pubescent . 



on the keel. 3. /.. nealleyi. 



Panicle of about 10 approximated and rather 

 widely spreading spikes; flowering 

 glume smooth. '». L. auOta. i 



