30 BULLETIN 545, U. S. DEPARTMENT OF AGRICULTURE. 



instances until the soil moisture was reduced to 7.5 per cent, though 

 two species died when there was a water content of 9.8 per cent. 



Flower stalks begin to appear during the first week in July and 

 continue until about the first week in August. The seed crop begins 

 to ripen as early as August 1 and continues throughout the month, 

 few immature seeds being found in September. The vitality of the 

 seed crop is about the average for upland grazing plants. The aver- 

 age germination for the three years of study was 21.2 per cent. 

 From this it would seem that many other species, such as moun- 

 tain wheat grass, which shows an average germination of 64 per 

 cent, would reproduce much more abundantly. Smooth wild rye, 

 however, is one of the most aggressive species on the high grazing 

 lands. The seedlings develop deep root systems, and a large per- 

 centage of the young plants succeed in rather adverse situations. 



The grazing value of smooth wild rye is high. By many stockmen 

 the plant is considered rather too coarse for sheep, though it is 

 probable that its forage value in this respect is underestimated, 

 since observations show that sheep readily graze it. Sheep rarely 

 crop the flower stalks, because these are produced exceptionally 

 early, and their rapid height growth soon puts the best part of them 

 out of reach of the animals, and because the stalks are somewhat 

 coarser than sheep relish and become unpalatable early in the sea- 

 son. All things considered, however, this plant furnishes good 

 forage by the time the upper ranges are grazed, and the herbage is 

 consumed ravenously throughout the season. Horses are fond of 

 the flower stalks, and until the seeds are matured and disseminated 

 the spikes or flower heads also furnish choice feed. Cattle graze the 

 forage closely even after the seed has been disseminated. 



White Foxtail. 



(Sitanion velutinum.) 



White foxtail, often called wild barley, to which it is closely related, 

 is undesirable on the range because of its low forage value and its 

 aggressiveness on overgrazed areas. 



The plant derives its name from the prominent awns, which, with 

 the entire spike, turn a light-straw color upon reaching maturity. 

 It is a tufted perennial grass from 1 to 2 feet tall, the culms rather 

 conspicuously spreading on the ground, the leaf blades mainly basal, 

 somewhat involute and rough, the upper surface pubescent. The 

 glumes are provided with long stiff awns, which, at maturity, are 

 strikingly divergent (Plate XXV) . 



White foxtail is most abundant in the Hudsonian zone. It is 

 also found on the lower grazing types, though not to the same extent 

 as on upland ranges. The situations most favorable to it are open 

 glades of rather poorly disintegrated soils with moisture content 



