55 



plants seldom seed in sufficient quantity to be troublesome. As soon 

 as the seed ripens the " spears'" fall and work into the soil, so that these 

 grasses can be used for hay or late grazing. 



The common needle-grass {Stipa comata) of this region is valuable for 

 both hay and pasturage. On poor rocky or gravelly soils, where it is 

 one of the characteristic species (see tig. 19), it affords a large amount 

 of pasturage, and on the rich prairie soils it makes a good yield of hay 

 which is considered by many ranchmen to be equal in quality to "blue- 

 stem" or wheat-grass hay. Here in the range region it takes the place 

 of porcupine-grass {Stipa spartea), so abundant in the Lower Missouri 

 Valley region, but which only occurs in any considerable quantity along 



Fig. 19.— a bit of the "range" in N. E. Wyoming. (Photographed by David Griffiths.) 



the eastern limits of the range. In some parts of the range, as for 

 examx)le in some localities of central and northern Wyoming, the com- 

 mon needle-grass sometimes composes the entire grass vegetation of 

 the sage-brush prairies. 



Another of the needle-grasses common in some of its many forms in 

 this region is that most commonly known as feather bunch-grass {Siipa 

 viridula). This is usually found in rather dry sandy soil, and forms 

 dense tufted masses of leaves and stems, which afford good grazing. 

 On account of its very blunt-pointed "spears" it seldom does any dam- 

 age to stock and, as it endures close feeding well, it is one of the most 

 desirable of the needle-grasses for grazing. Because of its densely 

 tufted habit of growth and less luxuriant production of root leaves it is 



