50 fip:ld wokk of division of agrostology. 



niiu-h Tike buffalo grass and ))liic o-raina orass, and replacos those spe- 

 cies largeh^ in western Texas and New Mexico. The })lack nies(|uite 

 or black grama {Hilaria mutlca), also called "gietta'' in New IVIexico 

 and Arizona, is a very important species and one of great value in this 

 region. Illlaria rlgida, stiff mes(|uite, is also called "gietta." It is 

 a rather coarse, harsh grass, growing in bunches, usuali}^ about 2 feet 

 high; being able to survive the most arid conditions it is of especial 

 value, as it is almost the only forage occurring in some places. It is 

 not a grass that would appeal to the fastidious tastes of stock accus- 

 tomed to the tender grasses of moister regions, but stock accustomed 

 to this region eat it with avidity. It is a very nutritious grass and 

 makes a very large growth immediately after a slight rainfall. Mr. 

 Orcutt mentions that it is said to cause death to horses and cattle in 

 case of stock just taken from alfalfa, but injury to range cattle from 

 this cause has not been reported. Perhaps next in importance to the 

 mesquite grasses are the g-rama grasses {Boitteloua spp.)- Bouteloua 

 erio}x>da^ woolly-foot grama, is one of the most valuable range grasses 

 in this region, especially in southern Arizona, New Mexico, and Texas. 

 It is a perennial, very hardy and nutritious, and is worthy of cultiva- 

 tion. Several other grama grasses are of more or less importance 

 here. The blue grama, which is such an important grass on the ranges 

 farther east, is not so abundant here. It occurs, however, in the 

 northern part of this region, and is of great value wherever found, 

 though not adapted to endure the extreme conditions of heat and drought 

 to be met with in many parts of this country. Six weeks' grama 

 {Bouteloua aristidoides) is an annual species which has assumed consid- 

 erable importance since the destruction of the better perennial grasses 

 (PL XXIV). It springs up immediately after the s\unmer rains, 

 growing very rapidly, as its name indicates, and producing considera- 

 ble feed during the autumn. Low grama {Bmitdoua poJydachija) is 

 another one of the so-called six weeks' grasses furnishing considerable 

 forage in many places immediately after the rainy season of this region. 

 Quite a number of other species of grama grasses occur, l)ut are less 

 abundant and important than the ones already mentioned. The triple- 

 awn grasses {Aristida spp.) are also of considerable importance. They 

 tend to spread and replace the better turf-forming grasses, which have 

 been destroyed. When young they are quite readily eaten by stock, 

 but w^hen they have reached maturity they are avoided by stock unless 

 driven to them by want of better feed. Several species of Muhle))- 

 hergla also furnish some feed in the foothills and canyons. A number 

 of species of /Sporoholus ("saccaton") are of considerable importance 

 in this region, especially Sjxrroholm crijptandnis, Sporoholus airoides^ 

 alkali fine top, and Sporobolm wrightii (Wright's saccaton). The lat- 

 ter species is an especially robust and luxuriant bunch grass, formerly 

 found in large quantities on the river bottoms of southern Arizona. 



