GEASSES OF AN ARID CLIMATE. 249 



The contrasted class of grasses adapted to arid cli- 

 mates may advantageously be examined next, and these 

 are all, or nearly all, natives of the interior and western 

 portions of this continent, where they are required. 

 Nutritious grasses of general range over the country 

 of their origin are few in number, while those growing 

 in particular localities, as in wet or sheltered spots, or 

 in others not representing the general surface, are quite 

 numerous everywhere. The principal of the new Amer- 

 ican grasses is the bunch grass (Festuca), the buffalo 

 grass, or small gramma, and the other species of gram- 

 ma grass (Bouteloua). 



The range of these is, for the last, or the gramma 

 grass proper, as given by Captain Marcy in his Report 

 on the survey of Red River, " bounded on the north by 

 near the parallel of 36 north latitude, and on the east 

 by the meridian of 98 west longitude. It extends south 

 and west indefinitely, but appears to flourish better in 

 about the latitude of 33 than any other. As there is 

 generally a drought on these prairies from about the 

 first of May to the middle of August, it would appear 

 that the particular varieties of grass growing here do 

 not require much moisture to sustain them." 



The buffalo grass, or small gramma, extends at least 

 to latitude 40 in the same longitude, and the asso- 

 ciated species called mezquite, with this, cover the 

 best portions of the valley of the Great Salt Lake, with 

 the entire country south and west on which rains fall at 

 any season. This whole family is extremely valuable, 

 seeding profusely, asd covering every portion of the 

 country where sufficient rain for its growth may be 

 found at any season. In the mountains a winter variety 

 is found remaining fresh, while that of the plains and 

 valleys is dried by the late summer heats. The whole 

 class is admirably adapted to the requirement of the 

 country, as they remain during the warmest months of 

 summer, and until the rains of the next season come 

 on, in a dried form, preserving the nutritive qualities 

 throughout. 



The precise time at which the heat and aridity check 



