FORAGE PLANTS 27 



or are protected by spines, are all more or less grazed by 

 stock, especially sheep. If there is an abundance of forage 

 the animals select the more palatable and nutritious spe- 

 cies. In overstocked areas the animals are forced more 

 and more to eat unpalatable or even poisonous species. 



On the prairies and plains of the western states, the 

 grasses form the chief element of the forage. The most 

 important single species probably is buffalo-grass (Par. 

 245). This is the dominant species on the Great Plains 

 from the Dakotas to Texas and from the Rocky Mountains 

 to the 100th meridian and beyond. This region is collo- 

 quially known as the "short-grass country," to distinguish 

 it from the prairie regions to the east, where tall grasses 

 prevail. On the plains of Texas and northern Mexico, 

 the buffalo-grass is gradually replaced by a species of 

 similar habit, the curly mesquite (Par. 212). 



The grama-grasses in numerous species in the West 

 and Southwest and on the table-land of Mexico form an 

 important and nutritive constituent of the ranges. The 

 most important of these is the blue grama, called in the 

 Southwest merely grama, and on the plains grama-grass, 

 extending from Manitoba to South America. Like buf- 

 falo-grass it is a "short grass" and is frequently confused 

 with that species. The three grasses, buffalo-grass, curly 

 mesquite and grama-grass, form a nutritious forage after 

 they have been cured in the autumn by the dry climate 

 of this region. Hence the range will support stock through- 

 out the winter if the conditions are favorable. Fall or 

 winter rains, or an early frost, decrease the value of the 

 forage. 



Other especially important western grasses are the 

 various species of Agropyron, Andropogon and Muhlen- 

 bergia. Pine-grass is important in Oregon and Washing- 



