THE AGRICULTURAL GRASSES OF THE UNITED STATES. 65 



are of about equal length and texture ; the seed is perfectly" round, 

 smooth and shining, thick and coriaceous. 



A writer on the grasses of the Rocky Mountains and plains in the 

 Agricultural Eeport for 1870 says : 



This species may be identified from its long, sleuder leaves, growing abundantly 

 from the base of the plant, gracefully curving and frecxuently resting their tips on the 

 ground ; from its tendency to grow branches or stools, and when in fruit, from its 

 small panicle of sharp-pointed spikelets and its round seeds. These when bruised emit 

 a strong, heavy oder, which has been compared to that of Erag7-ostis mef/aslachya when. 

 crushed in the hands; but to most olfactories it is much less offensive, and to some not 

 at all disagreeable. It attains to the average height of about 2^ feet in fruit, but in 

 dry seasons large tracts almost exclusively composed of this species are without a 

 single fruiting plant. It is sometimes cultivated for hay, in the absence of the more 

 productive species, and makes an article of fine quality. 



Sporobolus airoides. (Salt grass.) 



Culms arising from strong perennial creeping root-stalks, 2 to 3 feet 

 high, thickened at the base and clothed with numerous long, rigid, gen- 

 erally involute, long-pointed leaves, which are smooth and bearded in 

 the throat of the sheath, panicle becoming exerted and diffuse, 6 to 12 

 inches long, 3 to 4 inches wide ; the branches capillary, scattered, mostly 

 single, or in whorls below, the branches subdivided above the middle 

 and rather sparsely flowered. 



The spikelets are one-flowered, purplish, on short slender pedicels. 

 The outer glumes are unequal, thin, nerveless, or obscurely nerved, ob- 

 long, the lower half as long as the upper, the upper one rather shorter 

 than the flowering glume, which is about one line long, oblong, obtus- 

 ish or minutely dentate at the apex ; palet about equal to its glume ; 

 bidentate. 



A common grass throughout the arid regions of the West, sometimes 

 called salt grass, and affording considerable pasturage in some places. 

 (Plate 52.) 



Agrostis. (Bent grass.) 



This genus has many species all characterized by having one-flowered 

 spikelets; the outer glumes acute, one-nerved, and awnless, nearly equal, 

 or the lower rather longer, and longer than the flowering glume, which 

 is very thin, three to five nerved, awnless or awned on the back ; jyalet 

 shorter than the flowering glume, frequentlj^ reduced to a small scale or 

 absent. 



Agrostis vulgaris. (Red top, Fine top. Herd's grass of Pennsyl- 

 vania Borden's grass, Bent grass.) 

 A perennial grass, growin"g 2 or 3 feet high from creeping root-stocks, 

 which interlace so as to make a very firm sod ; the culms are upright, or 

 sometimes decumbent at the base, smooth, round, rather slender, and 

 clothed with four or five leaves, which are flat, narrow, and roughish, 

 from 3 to 6 inches long, with smooth sheaths, and generally truncate 

 2218 GR 5 



