IMPORTANT RANGE PLANTS. 29 



up to about August 15, but considerably later in the season, even in 

 September, the basal leaf blades, though not the flower stalks, are 

 eaten close to the ground by sheep and cattle. Mountain wheat 

 grass is cropped in preference to a large number of species. It is 

 preferred in the latter part of the season, if not earlier in the year, 

 to big bunch grass, though its scattered growth and narrow zonal 

 distribution make it less important than the latter. 



A species closely allied botanically to mountain wheat grass is 

 red bunch grass (A. flexuosum) , so named on account of its reddish- 

 purple panicles and bunched habit of growth (PI. XXIII). Its 

 prominent awns and loose spikes, however, give a very different 

 appearance from the former. It is sometimes mistaken for smooth 

 wild rye (PL XXIV) , though very different in structure. In its range 

 of distribution, ecological requirements, period of flower stalk pro- 

 duction and seed maturity, and in its forage value, red bunch grass 

 is very similar to mountain wheat grass, though in most situations it 

 does not remain palatable as late in the season. 



SMOOTH WILD RYE. 

 (Elymus glaucus.} 



The species belonging to this genus are generally known as rye 

 grasses because of their resemblance to the ordinary cultivated rye. 

 There are about 25 species of Elymus, distributed mainly throughout 

 the north temperate regions. 



Smooth wild rye is a perennial bunch grass with a strong root system 

 capable of withstanding more than the average trampling by stock. 

 It grows from 1 to 3 feet in height, the sheaths enveloping the culms 

 usually being smooth, the leaves abundant, smooth beneath, some- 

 times rough above. The spike, 2 to 5 inches long, is narrow and 

 slender, bearing numerous spikelets of three to six flowers. The 

 glumes (lowermost empty two scales) are narrow, sharp pointed and 

 rigid. The lemmas (upper flowering scales) smooth or slightly rough, 

 each bearing a straight rough awn one-fourth to one-half inch in 

 length. 



This grass is distributed over a wide altitudinal range. It is most 

 abundant in the upper Canadian zone, is fairly common in the lower 

 Hudsonian zone, and is found to a limited extent in the Arctic- 

 ilpine zone. As a rule, its growth is not dense, but affords an abun- 

 dance of forage because of its wide distribution. In most cases it is 

 merged with mountain bunch grass, short-awned bromegrass, and 

 other species characteristically associated with the latter in glades 

 and parks. Smooth wild rye seems to be somewhat better able to 

 succeed in moister habitats than many of the plants associated with 

 it in exposed situations, and yet it withstands drought remarkably 

 well. In the drought tests it did not wilt beyond recovery in some 



