Stipa spartea (Northern buffalo-grass; wild oat).—­This grass is found in southern Manitoba, westwardly across the plains to the Rocky Mountains, and southward as far as Montana, where it is common in many localities.  On what was once the buffalo range of the British Possessions this rank grass formed the bulk of the winter pasturage, and in that region is quite as famous as our grama grass.  An allied species (Stipa viridula, bunch-grass) is “widely diffused over our Rocky Mountain region, extending to California and British America, and furnishing a considerable part of the wild forage of the region” Stipa spartea bears an ill name among stockmen on account of the fact that at the base of each seed is a very hard and sharp-pointed callus, which under certain circumstances (so it is said) lodges in the cheeks of domestic animals that feed upon this grass when it is dry, and which cause much trouble.  But the buffalo, like the wild horse and half-wild range cattle, evidently escaped this annoyance.  This grass is one of the common species over a wide area of the northern plains, and is always found on soil which is comparatively dry.  In Dakota, Minnesota, and northwest Iowa it forms a considerable portion of the upland prairie hay.

Of the remaining grasses it is practically impossible to single out any one as being specially entitled to fourth place in this list.  There are several species which flourish in different localities, and in many respects appear to be of about equal importance as food for stock.  Of these the following are the most noteworthy: 

Aristida purpurea (Western beard-grass; purple “bunch-grass” of Montana).—­On the high, rolling prairies of the Missouri-Yellowstone divide this grass is very abundant.  It grows in little solitary bunches, about 6 inches high, scattered through the curly buffalo-grass (Bouteloua oligostachya).  Under more favorable conditions it grows to a height of 12 to 18 inches.  It is one of the prettiest grasses of that region, and in the fall and winter its purplish color makes it quite noticeable.  The Montana stockmen consider it one of the most valuable grasses of that region for stock of all kinds.  Mr. C. M. Jacobs assured me that the buffalo used to be very fond of this grass, and that “wherever this grass grew in abundance there were the best hunting-grounds for the bison.”  It appears that Aristida purpurea is not sufficiently abundant elsewhere in the Northwest to make it an important food for stock; but Dr. Vesey declares that it is “abundant on the plains of Kansas, New Mexico, and Texas.”

Koeleria cristata.—­Very generally distributed from Texas and New Mexico to the British Possessions; sand hills and arid soils; mountains, up to 8,000 feet.

Poa tenuifolia (blue-grass of the plains and mountains).—­A valuable “bunch-grass,” widely distributed throughout the great pasture region; grows in all sorts of soils and situations; common in the Yellowstone Park.