THE AGRICULTURAL GRASSES OF THE UNITED STATES. 75 



lower one being very narrow and awl-shapecl, the upper one broad, three- 

 nerved, obtuse, and tipped with a fine j)oint, and longer, sometimes twice 

 as long as the lower. 



The flowering glume has two slender pointed teeth, and on the back, 

 near the apex, a slender awn twice its length. 



Of this grass Mr. Bolander says that it deserves further attention. 

 It grows on dry hill-sides near the Bay of San Francisco and the Oak- 

 land hills, and also extends northward to Oregon. (Plate 66.) 



TmSETUM SUBSPICATUM. 



A perennial grass of the mountainous regions of Europe and North 

 America. It is found sparingly in New England, on the shores of Lake 

 Superior, in the Kocky Mountains of Colorado, Utah, California, Oregon, 

 and northward to the Arctic circle. It varies in height according to the 

 altitude at which it grows, being sometimes reduced to 3 or 4 inches, at 

 other times running up to 2 feet high. The culms are erect and firm, 

 smooth, or downy. The panicle is spike-like, dense, and cylindrical or 

 elongated, and more or less interrui)ted, generally of a purplish color. 

 The spikelets are two to three flowered. The flowers are slightly longer 

 than the outer glumes, slightly scabrous, the flowering glumes acutely 

 two toothed at the apex, and bearing a stout awn which is longer than 

 its glume. 



This undoubtedly furnishes a considerable portion of mountain pas- 

 turage. (Plate 67.) 



A VENA. (Oats and Oat grass.) 



This genus is closely related to THsetiwi, the spikelets are larger and 

 two to five flowered, the uppermost one generally imperfect; the axis is 

 hairy below the flowers, the outer glumes nearly equal ; the flowering 

 glumes of firmer texture (in some species cartilaginous), shortly two- 

 toothed at the apex, and with a long twisted awn below the point. 



Ayena fatua. (Wild oats.) 



This species is very common in California. It is generally thought 

 to have been introduced from Europe, where it is native, but it has be- 

 come diffused over many other countries, including Australia and South 

 America. It is thought by some to be the original of the cultivated 

 oat, Avena sativa^ that the common oat will degenerate into the wild 

 oat, and that by careful cultivation and selection of seed the wild oat 

 can be changed into the common cultivated oat. But on this question 

 there is a conflict of opinions, and the alleged facts are not sufficiently 

 established. The wild oat difi'ers from the cultivated one chiefly in 

 having more flowers in the spikelets, in the long brown hairs which 

 cover the flowering glumes, in the constant presence of the long twisted 

 awn, and in the smaller size and lighter weight of the grain. It is a 

 great injury to any grain-field in which it ma3^ be introduced, but for 



