106 
Journal of Agricultural Research 
Vol. XXVIII, No. 2 
too arid to use for crop production unless additional moisture is available from 
flooding. The kind and amount of crops raised would depend upon the quantity 
of flood water. Tobosa grass is grazed when green but is practically worthless 
when dry. 
(34) Galleta ( Hiiaria jamesii (Torr.) Benth.).—Galleta grass is found in 
pure stands in this type. It is usually grazed rather closely so that it forms an 
even turf. This species is common in New Mexico and eastern Arizona but it 
occupies rather small areas. In Utah and Nevada, however, it occurs over 
rather large areas and it constitutes one of the best grazing types in the Great 
Basin. Very good grazing for all classes of livestock and can withstand heavy 
grazing. Usually more valuable for the native forage it provides than for growing 
cultivated crops. The carrying capacity varies considerably according to the 
density of the galleta. On most areas, however, the grazing capacity will range 
from 25 to 100 head of cattle per section. 
(35) Crowfoot Grama ( Bouteloua rothrockii Vasey).—This species while 
found in combination with other species often forms pure stand and during wet 
years it makes sufficient growth on the more favorable habitats to cut for hay. 
Common in Arizona on mountain mesas and mountain foothills where it occupies 
a deep black loam soil. The most favorable habitats of this type can be used for 
producing cultivated forage crops. Crowfoot grama is highly palatable and 
nutritious but will not stand heavy grazing. It has a carrying capacity of from 
20 to 35 head of cattle per section. 
(36) Hiiaria rigida Benth.—This grass resembles a shrub in its coarse up¬ 
right growth. Its range is limited largely to the Colorado desert where it is 
frequently found in pure stands of rather scattered bunches. It develops best 
in areas where sand is slowly being deposited over the soil. It is almost too coarse 
to be readily taken by stock but is one of the main perennial grazing plants in the 
desert regions, so that it affords considerable feed. The habitat of this species 
is too arid to produce any cultivated crop without irrigation. It has a carrying 
capacity of from 2 to 10 head of cattle per section. 
(37) Tussock Grass ( Sporobolus airoides Torr.).—Tussock grass, illustrated 
in Plate 5, A, is a rather coarse-tufted grass forming a big bunched growth often 
a foot in diameter at the base. It is common along water courses on rather heavy 
alkaline or “gyp” soils in the southern Great Basin, New Mexico, and Arizona, 
and adjacent portions of the High Plains. Readily grazed by cattle and horses 
when green. It is most abundant on aklali land that receives some flood water. 
Lands occupied by this type usually contain too much alkali to be used for growing 
crops. It affords the best grazing of any of the alkali grasses, having a carrying 
capacity of from 50 to 100 head of cattle per section. 
(38) Sacaton ( Sporobolus wrightii Munro).—Sacaton grows in tall coarse 
bunches forming a dense bunchlike stand on deep alluvial land relatively free 
from harmful amounts of alkali. It therefore characterizes land excellent for 
irrigation. It is found in eastern Arizona, New Mexico, and western Texas. 
Sacaton makes good hay, especially for horses. It is fairly good for grazing but 
is easily killed out by excessive tramping. It has a carrying capacity of from 50 to 
100 head of cattle per section. ^ 
(39) Wheat Bunchgrass ( Agropyron spicatum (Pursh) Rydb.).—The wheat 
bunchgrass type illustrated by Plate 5, B, is applied to open grass lands com¬ 
posed almost entirely of wheat bunchgrass. This is the dominant type in the 
Columbia River Basin in Washington and below the timber zone in northeastern 
and north-central Oregon. It is also common in the rolling foothills and lower 
plateaus of Idaho and northern Utah, growing on well-drained loamy soils. 
Most of the best wheat lands of Oregon and Washington were originally vegetated 
by this type, so where it is growing in dense thrifty stands it is indicative of 
