Apr. 12,1924 Vegetation in the Semiarid Portion of the United States 109 
high, having twisted gnarled stems, and a comparatively small amount of foliage, 
are classified in this type. It occurs principally on the scablands in Washington 
and Oregon, growing on rocky soil, wholly unsuited for crop production. The 
grazing value is poor, less than 10 head of cattle per section. 
(52) Hop-Sage ( Grayia spinosa (Hook.) Moq.).—Hop-sage resembles sage¬ 
brush when not in leaf, but has thick fleshy leaves which contrast sharply with 
the thin silvery leaves of the sagebrush. It is called “hop-sage” because of the 
character of the fruits which resemble hops. This species is very abundant and 
has a wide range throughout the very arid sections of the West, particularly 
Nevada and western Utah. It is also found in the Red Desert of Wyoming, 
growing with shadscale and sagebrush. Land characterized by this type is of 
little or no value for crop production unless irrigated. It is of little forage 
value except as winter range for sheep. 
(53) Antelope-brush ( Purshia tridentata (Pursh) DC.).—The antelope-brush 
type, shown by Plate 7, B, is dominant in sandy soils along the Columbia River 
in Washington and Oregon. It also occurs through the Great Basin region as 
well as in California. As a rule it is associated with sagebrush. Together they 
usually characterize land more rocky and therefore less suited to crop production 
than pure sagebrush. They supply a fair browse for cattle and sheep, having a 
carrying capacity of 20 to 30 head of cattle per section. 
(54) Shadscale ( Atriplex confertifolia (Torr.) S. Wats.).—Plate 8, A, illustrates 
a typical shadscale area which supports scattered even stands of shadscale, 
the plants ranging from 6 inches to 2 feet in height and usually presenting a uni¬ 
form rounded appearance. The leaves are leathery and seeds are produced in 
abundance. Plants are spiny and too rigid to be moved by an ordinary wind. 
This is a very common and widely distributed type in the Great Basin, growing 
frequently in rather heavy alkaline soils. In most localities it characterizes a 
shallow soil with alkali in the second foot and also to a lesser extent in the first 
foot. It is nonagricultural unless irrigated and drained to remove excess alkaline 
salts. It is one of the main plants grazed by sheep on the winter ranges. It 
has a carrying capacity of 25 to 100 head of sheep per section for a short in¬ 
termittent grazing period. 
(55) Salt Sage ( Atriplex corrugata S. Wats, and A. nuttallii S. Wats.).—This 
species, also known as saltbush, illustrated by Plate 8, B, grows in low mats 
varying in size from a few inches to several feet across and seldom exceeding 6 
inches in height. The mats are often scattered over an otherwise barren surface. 
It is found in rather heavy saline soils in southwestern Wyoming, west-central 
Colorado, east-central and western Utah, and Nevada. Readily browsed by 
sheep during the winter season. Growth occurs very early in the season, and it 
is then readily grazed by sheep. It has a carrying capacity of 25 to 75 head of 
sheep per section. This species indicates nonagricultural land, owing mainly to 
the high alkali content of the soil. 
(56) Little Rabbitbrush ( Chrysothamnus stenophyllus (A. Gray) Greene).— 
This type, illustrated by Plate 9, A, is applied to lands containing a rather even 
growth of small bunches, or of scattered larger bunches, of little rabbitbrush. 
Flowers are produced in great quantity and the area presents a uniform bright 
yellow color during the flowering period. The bushes are often as much as 2 
feet high, but usually much smaller. It is indigenous to Utah and Nevada on 
light soils free from alkali. This species very frequently comes in on burned 
sagebrush and shadscale land. It has little value as grazing land. 
( 57 ) Rabbitbrush ( Chrysothamnus graveolens (Nutt.) Greene), and Tussock 
Grass. —Lands containing a fairly even or occasionally matlike sod of tussock 
grass over which are scattered plants of rabbitbrush are classified in this type. 
Areas supporting this type have too much alkali for growing cultivated crops. 
