IMPORTANT RANGE PLANTS. 23 



which the species grows on the higher ranges, and second, to the 

 inherent tendency of the species to complete its development at a 

 very early date in its lower zone. The flower stalks on the upland 

 ranges appeared from July 10 to August 1, July 10 to August 10, and 

 July 5 to August 5, in 1907, 1908, and 1909, respectively. The seeds 

 began to ripen in the latter part of July, and, except in 1907, the 

 seed crop had matured by August 20. 



The seed crop developed in the high mountains has a low vitality, 

 the average for all tests made for the Hudsonian zone for the three 

 years being only 7 per cent. In contrast to this, seed grown in the 

 Transition zone showed average germination of 38.4 per cent. 



As a forage for sheep, horses, and cattle early in the season, little 

 bluegrass can hardly be surpassed. The entire plant is readily con- 

 sumed until the seeds begin to reach full development. After the 

 seeds have matured, however, which they do early in the summer, 

 the plant is neglected for the more palatable tender species. In the 

 fall of the year, when the bulk of the range plants are air-cured, 

 little bluegrass again becomes one of the choice species. 



Other bluegrasses occur in the mountains, but as a rule are so 

 scattered as not to merit special mention. The species most com- 

 monly met with, in order of their abundance, are P. Irachyglossa, 

 P. paddensi.s, and P. ampla. 



SHORT-AWNED BROMEGRASS. 

 (Bromus marginatus.) 



The genus Bromus is closely related botanically to Festuca, to 

 which mountain bunchgrass belongs. In general, it differs in having 

 larger spikelets and a toothed apex on the lemma, or flowering glume. 



Short-awned bromegrass (Plate XVIII) is a perennial species, and 

 on favorable situations almost invariably forms a dense turf. The 

 culms are erect and stout, from 3 to 4 feet in height, the sheaths 

 are usually clothed with scattered, rather long, soft hairs ; the panicle 

 is erect and somewhat narrow, of a purple cast, and from 4 to 8 

 inches long, with seven to nine flowered spikelets, the florets coarsely 

 pubescent, with two rather pointed hyaline teeth at the apex and 

 the midrib extending into an awn one-fourth inch long. 



Short-awned bromegrass has rather a wide distribution in the 

 region studied, but grows most luxuriantly between 4,000 and 7,500 

 feet elevation, where it generally inhabits the better soils of medium 

 moisture content. 



It grows in dry situations on open plateaus, in friable loam soils, 

 and in canyons, and often predominates on the banks of streams. 

 The plant did not wilt destructively until the moisture in the soil 

 was reduced to between 5.5 and 8 per cent. 



