ATLAS OF AMERICAN AGRICULTURE. 
Figure 57.—Greasewood in a semidormant condition. (Greasewood.) Characteristic of moist, mod¬ 
erately saline soils. It is gray and sagelike in winter and bright green during the growth period. The 
luxuriant growth is deceptive, since the soluble salt-content of the soil is so high that only with leaching 
and careful irrigation can the land be made productive. It is characteristic of the bottom of the valleys, 
where for the most part ground water furnishes part of the moisture supply. The transition from this type 
to the shadscale is usually very gradual. Lund, Utah. 
Figure 58.—A pure stand of seepweed, characteristic of moist, strongly saline soils, where the ground 
water rises to or near the surface. (Greasewood.) Plants are about 3 feet high, and commonly purple in 
color, especially late in the season. The amount of salt in the soil is usually greater than in soils grow¬ 
ing greasewood, and the land is of doubtful agricultural value. Thermal, Calif. 
region, greasewood ( Sarcobatus vermiculatus) is often 
scattered through an even stand of shadscale {Atriplex 
confertifolia) . The appearance is varied, since the 
shadscale plants are ashen in color and the greasewood 
plants bright green. The condition indicated is inter¬ 
mediate between pure shadscale and pure greasewood, 
namely, a soil containing alkali in the second or third 
foot but with ground water limited to the deeper soil, 
not available to the shadscale but available at least 
during a part of the year to the deep-rooted grease¬ 
wood. 
Figure 59.-—A salt flat with scattered hummocks of pickleweed. 
(Greasewood.) Green plants contrast sharply with salt-covered 
soil. Soil contains 2 or more per cent of soluble salts. Lower 
Death Valley, California. 
Seepweed (fig. 58).—Throughout the entire range of 
the salt desert shrub, seepweed {Dondia torreyana) 
occupies land nearer the local water level and a little 
higher in salt content than that occupied by grease¬ 
wood. The plants range in height from 1 to 4 feet, are 
very finely branched, and often purple or dark in color, 
especially in the latter part of the growing season. 
PicMeweed (fig. 59).—On the great salt-flats hum¬ 
mocks of pickleweed ( Allenrolfea occidentalis) oc¬ 
cur, while on soil more favorable for plant growth 
the plants may have an even distribution and. form a 
relatively close cover. In the southern desert region 
the plants are often 3 or 4 feet high, but as a rule are 
much smaller in the northern desert region. They are 
of dark-green color and very succulent. This type 
occurs at a lower level than the greasewood and on soil 
which contains more moisture and is more strongly im¬ 
pregnated with salts. The conditions, therefore, are 
much more extreme than those indicated either by 
greasewood or seepweed. Over much of the surface 
salt incrustations give the soil an almost snowlike ap¬ 
pearance. Large areas occur near Salt Lake, and on 
the alkali flats in Nevada, Arizona, southeastern Cali¬ 
fornia, and in the San Joaquin Valley. 
Samphire (fig. 60) .—Conditions very similar to those 
indicated by pickleweed are found where the samphire 
grows. The soil contains as a rule about 2.5 per cent of 
soluble salt and usually is supplied with ground water 
at a relatively short distance below the soil surface. 
The conditions are the most extreme encountered under 
any type of vegetation in the salt desert shrub. In the 
region about Great Salt Lake, where it is widely dis¬ 
tributed, it is composed of the perennial Utah samphire 
(Salicornia utahensis ) and the annual red samphire 
(Salicornia rubra). The annual form is greatly fa¬ 
vored by precipitation which leaches slightly the sur¬ 
face soils, and germination is usually best along the 
drainage channels. The perennial form occurs on scat¬ 
tered hummocks or may form a practically pure even 
stand. The appearance of the two species is very dif¬ 
ferent, since the annual is a bushlike plant 2 to 6 
inches high, which turns very red toward the end of the 
growing season, while the perennial pushes up almost 
unbranched stems and does not take on an autumn 
coloration. Along the coast the salt marshes are simi¬ 
lar to the inland areas, but are usually inundated at 
high tide by ocean water, and are dominated by a dif¬ 
ferent species ( Salicornia ambigud). These areas are 
too limited to be shown on the map. 
Salt grass. —Alkali flats, especially those over which during 
flood time a supply of fresh water flows, usually develop a 
salt-grass cover. Salt grass ( Distichlis spicata ) is a low- 
growing grass and forms either an open cover with occasional 
plants from underground runners showing at the surface, or 
under more favorable conditions a uniform dense sod, in 
which few other species are prominent. Salt-grass pastures 
miles in extent occur along many of the watercourses in 
the Great Basin, the Colorado and Rio Grande deserts, east 
of the mountains on the Great Plains, in the San Joaquin 
Valley, and along the coasts. The appearance of this type 
of vegetation is not markedly different from that of a closely 
grazed meadow, or of the plains or desert grassland. The 
principal value of land of this type is for grazing. Only with 
careful management and some leaching does it produce crops 
under irrigation. The salt content is generally high (about 1 
per cent). The soil moisture is supplied from ground water 
as well as by flood water and precipitation. 
Tussock, grass. —Under conditions a little more favorable 
than those found on salt-grass land, tussock grass ( Sporobolus 
airoides) forms either a relatively close sod or a hummocky 
open cover. This grass is usually closely grazed by rabbits 
Figure 60.—Hummocks of Utah samphire on salt flat. (Grease¬ 
wood.) Characteristic of continuously moist salt flats containing 2 
or more per cent of soluble salt. Great Salt Lake, Utah. 
and by cattle and horses and contributes materially to the 
forage production of the region. If not grazed closely this 
grass is marked by a feathery purple panicle during the flow¬ 
ering period. 
Rabdit brush. —In many places rabbit brush ( Ghrysotham - 
nus graveolens) is scattered over a tussock-grass sod, and 
often becomes so dense that only the brush is evident. The 
yellow-flowered shrubs stand from 2 to 5 feet high; they grow 
rapidly and are relatively short-lived. 
Alkali heath. —In the San Joaquin Valley alkali heath 
(Frankenia grandiflora campestris) , pure or mixed with grease¬ 
wood or salt grass, is one of the most important salt desert 
plants. 
