26 A TEXT-BOOK OF GRASSES 



been tried along this line but with little success. The area 

 involved is too large and the expense is too great. There is 

 the further difficulty of finding plants better adapted to 

 the conditions than those that primarily occupied the soil. 



The plants that tend to come in to replace those sub- 

 dued by grazing are usually weedy annuals that have 

 little forage value. Such are the numerous species of Old 

 World brome-grasses that are now so common on the 

 Pacific slope and in some portions of the region to the 

 east of this. There is one exception to this, the annual 

 herbaceous plant known as alfilaria or "filaree" {Erodium 

 dcutarium (L.) L' Herit.) a member of the geranium 

 family. This is an excellent forage plant and is gradually 

 spreading on the ranges of the Southwest. 



The only practicable method to rejuvenate worn-out 

 ranges is to give them rest. If stock is kept from them they 

 will in time return to a condition of productiveness. The 

 length of time necessary for an overgrazed range to recu- 

 perate depends upon many conditions. If the overgrazing 

 has been for a short period a single season of rest may be 

 sufficient. If a considerable portion of the original vege- 

 tation has been destroyed two or three seasons may be 

 necessary. In the latter case the resulting vegetation will 

 probably be different from the original and may be less 

 valuable. Thoughtful ranchmen are learning to conserve 

 their ranges by regulation and rotation and by limiting 

 the stock to the carrying capacity of the range. (See 

 Bur. PI. Ind. Bulletin No. 117 and Yearbook for 1906.) 



Range grasses 



23. The wild plants upon the range, unless they are 

 positively distasteful because of bitter or acrid substances 



