WOOTON AND STANDLEY FLORA OF NEW MEXICO. 87 



7. Bouteloua eriopoda Torr. U. S. Rep. Expl. Miss. Pacif. 4: 155. 1856. 



Black grama. 

 Chondrosium enopoclum Torr. in Emory, Mil. Reconn. 154. 1848. 

 Type locality: Along the Rio Grande, New Mexico. Type collected by Emory. 

 Range: Arizona and western Texas to Mexico. 



New Mexico: Common tlirougliout the State except iu the extreme northeast. 

 Dry liills and plains, in the Lower and Upper Sonoran zones. 

 This is one of the most valuable range grasses in the southern part of New Mexico. 



8. Bouteloua breviseta Vasey, Contr. U. S. Nat. Herb. 1: 58. 1890. 

 Ty'pe locality: Screw Bean, Presidio County, Texas. 



Range: Western Texas and southern New Mexico. 



New Mexico: \niite Sands; Lakewood; Carlsbad. Dry plains, in the Lower Sono- 

 ran Zone. 



9. Bouteloua hirsuta Lag. Var. Cienc. 2*: 141. 1805. Hairy grama. 

 Chondrosium Mrtum H. B. K. Nov. Gen. & Sp. 1: 176. pi. 59. 1816. 

 Chondrosium Joeneum Torr. in Emorj^ Mil. Reconn. 154. pi. 12. 1848. 



Ty'pe locality: Described from cultivated plants. 



Range: Colorado and Nebraska to Mexico and Florida. 



New Mexico: Pecos; Clayton; Nara Visa; Silver City; Socorro; Torrance; Organ 

 Mountains; Dona Ana Mountains; Leachs; Buchanan. Dry hills, in the Lower and 

 Upper Sonoran zones. 



The type of Chondrosium foeneum was collected by Emory along the Rio Grande. 



10. Bouteloua gracilis (H. B. K.) Lag.; Steud. Nom. Bot. ed. 2. 1: 219. 1840. 



Blue grama. 



Chondrosium gracile H. B. K. Nov. Gen. & Sp. 1: 176. pi. 58. 1S16. 



Atheropogon oUgostachyum Nutt. Gen. PI. 1: 178. 1818. 



Bouteloua oligostachya Torr.; A.Gray, Man. ed. 2. 553. 185.3. 



Ty'pe locality: "Crescit in crepidjnibus et devexis montis porphyritici La Buffa 

 de Guanaxuato Mexicanorum, alt. 1270 hexa,p." 



Range: British America to California, Missouri, and Mexico. 



New Mexico: Common tliroughout the State except at lower levels. Meadows 

 and hillsides, in the LTpper Sonoran and Transition zones. 



Blue grama is undouljtedly the most valuable forage plant of New Mexico. It 

 occurs generally on the higher plains and lower mountains at altitudes of from 1,800 

 to 2,400 meters, often forming nearly pure stands. When not molested it becomes 

 knee-high, and a large field in such a condition is a beautifid sight because of the 

 myriads of purple spikes. The grass is resistant to overgrazing and is able to spread 

 rapidly when not too closely grazed. 



This has generally been known as Bouteloua oligostachya, a name which, unfortu- 

 nately, lacks priority. 



49. CHLORIS Swartz. 



Mostly perennials with flat leaves and rather showy inflorescence of 2 to many 

 digitate spikes; spikelets ]-flowered, awned, sessile in 2 rows along one side of a con- 

 tinuous rachis, forming unilateral spikes; rachilla jointed above the glumes and pro- 

 duced beyond the palea, bearing 1 or more empty rudimentary awned glumes; glumes 

 unequal, lanceolate, acute, somewhat keeled; lemma narrow or broad, 1 to 3-nerved, 

 acute to truncate or emarginate or 2-lobed, often cUiate on the back or margins, the 

 middle nerve usually prolonged into an awn; grain free. 



