34 MISC. PUBLICATION 101, U. S. DEPT. OF AGRICULTURE 
most valuable winter forage plants on the low, dry areas where it 
grows. 
GREASEWOODS (SARCOBATUS SPP.) 
Sarcobatus is a genus of two west-American species, S. vermicu- 
Zatus and the smaller, spinier, darker-barked, more downy, larger- 
fruited S. baileyi, syn. S. vermiculatus baileyi, of the Colorado and 
Mohave Deserts. 
Greasewood (Sarcobatus vermiculatus) (fig. 5), sometimes called 
“black greasewood,” also “chico” by Spanish-speaking people, is a 
shrub 2 to 10 feet high with a bark that in the young plants is whit- 
ish, but in the older plants is grayish sometimes verging on black. It 
has rigid, intricate branches, many of the twigs becoming thorn- 
like, or spinelike at the tip, and small linear fleshy leaves. A general 
cleaginous appearance is reflected in the vernacular name. 
This shrub is found in every State west of the one-hundredth 
meridian and in southwestern Canada as well. It is characteristic 
of semiarid or arid alkaline plains at elevations of 5,000 to 8,000 feet 
in the South and 2,000 to 4,000 feet in the North, and is often exceed- 
ingly abundant. The species is especially characteristic of black 
alkali? sites—so much so that places where it occurs are deemed 
impossible of reclamation for agricultural purposes. The physical 
properties of the soils it inhabits exhibit the greatest variation, from 
the heaviest adobe to light sandy soils. It is, with the exception of 
burroweed, often called pickleweed (Allenrolfea), probably the most 
alkali-resistant of native American shrubs (20, p. 233-236; pl. 53). 
Saltbushes and saltgrass (Dvstichlis spicata) are frequent associates 
of greasewood. 
Jared G. Smith (724) calls attention to the fact that greasewood, 
because of its deep and broad root system, absorbs large quantities of 
soda salts, much of which finds its way into the leaves during the 
natural processes of growth. As the leaves fall, there is an accumu- 
lation or concentration of soda in the surface soil. Ash analyses 
of the plant at the New Mexico Agricultural Experiment Station 
showed 22 per cent of potash and 23.9 per cent of soda. 
Greasewood is an important range browse; in fact it prevents many 
saline areas of vast extent from being almost worthless. In some 
places it is one of the most valuable winter sheep and cattle feeds, 
although hardly the equal of winter fat or perhaps of big sagebrush 
(Artemisia tridentata) in this respect. Horses and goats also crop 
it. The leaves, younger stems, and especially the seeds are consumed, 
the natural saline taste doubtless enhancing the palatability. As 
these parts are all produced in great profusion, and the form, stature, 
and open stand are conducive to full utilization, the species is a heavy 
forage producer. In fact, its normal height of 3 to 5 feet on the 
range is probably due to grazing; in wholly protected areas the 
average height is often several feet greater. Because of the high 
alkaline content of the herbage, livestock undoubtedly do better on 
a greasewood range when given supplemental feeding, fresh water 
in quantity, or both. Moreover, if greasewood is eaten in too great 
concentration, definite symptoms of poisoning may result. Couch 
7 Black alkali_is the result of the reaction of sodium carbonate (sal soda, or washing 
soda, NazCO3;H2O) and soil humus, and is extremely deleterious to nearly all plant life, 
