NATIVE PASTURE GRASSES OF THE UNITED STATES. 



39 



POA BIGELOVII Vasey & Scribn. 



Poa bigelovii is a typical species of the Mexican-boundary region of Arizona. What 

 its habits were originally we do not know, but at the present day it grows almost 

 invariably in the protection of shrubbery in the foothills at an altitude of 3,500 to 

 5,000 feet. It seems to desire protection from the sun as well as from live stock. In 

 these situations it furnishes a small quantity of grazing of a fairly good quality. It 

 undoubtedly is not as good feed as the perennial species of Poa, but it grows in this 

 region as a winter and early-spring annual when the stock feed is made up almost 

 entirely of weedy, nongrass forage plants. 



No. 9167 was collected in the foothills of the Santa Rita Mountains, Arizona, April 

 10, 1908. The sample was nearly mature and was cut close to the ground. Its per- 

 centage of moisture was 9.30. "Other constituents (on a water-free basis) were as 

 follows: Ash, 7.35; ether extract, 2.93; crude fiber, 24.39; nitrogen-free extract, 58.26; 

 protein, 7.07; pentosans, 16.37. 



POA LAEVIGATA Scribn. 



Poa laevigata, although somewhat distantly related to the common cultivated blue- 

 grass, is quite wiry, but it is still a very important pasture and hay grass in the edges 

 of moist bottoms of the interior Great Basin and Rocky Mountain regions. The situa- 

 tions most suitable for its development are those which receive one or possibly two 

 good floodings during the year. This is characteristic of the heavy, hard, adobe soils 

 between the lower moist bottoms and the surrounding ridges in the eastern part of 

 this range and of the sinks and swales of the Great Basin. In such situations, this 

 species often grows luxuriantly, in almost perfect stand, and will sometimes cut lh 

 tons of hay to the acre. It makes a good quality of hay and, when properly handled, 

 a good grade of pasture. Its seed habits are as good as those of Kentucky bluegrass. 



No. 8840 was collected at Virdon, Mont., August 14, 1907. The specimen was over- 

 mature. It was cut about 1 inch above the ground. 





Percent- 

 age of 

 moisture. 



Water-free basis (per cent). 



Material analyzed. 



Ash. 



Ether 

 extract. 



Crude 

 fiber. 



Nitrogen- 

 free 

 extract. 



Protein. 



Pento- 

 sans. 



Our sample No. 8840 



4.36 



5.04 

 10.96 



2.56 

 2.17 



33.96 

 38.27 



55.11 



42.87 



3.33 

 5.73 



27.32 

















8.00 



2.37 



36.11 



48.99 



4.53 











i Montana Report, 1902, p. 66. 

 POA NEMORALIS L. 



Poa nemoralis is a valuable species which reaches its characteristic development in 

 woodland meadows and has a wide distribution in both the North American and 

 Eurasian continents. There are few species that possess such an altitudinal varia- 

 tion of distribution. It ranges from 2 or 3 inches in height at the snow line to 2 feet 

 or more in favored situations at the base of the mountain. While it is an important 

 grass and one relished by all kinds of live stock, it is never abundant enough to be of 

 first importance. It commonly grows in large isolated bunches in favorable situations 

 at lower levels; higher up in the mountains the bunches are smaller and the plants 

 more dwarfed. In palatability to stock and general characteristics of value it stands 

 very close to Kentucky bluegrass. Its habits of growth, however, are not as good. 

 Its seed habits are just as desirable for a cultivated species as those of Kentucky 

 bluegrass. 



No. 8869 was collected at Summit, Mont., August 15, 1907. The specimen was 

 in early blossom and was cut close to the ground. 



