6 MISC. PUBLICATION 101, U. S. DEPT. OF AGRICULTURE 
In the Southwest and in the southern Great Basin region numerous 
shrubs with slender, decidedly green twigs are palatable; the stems 
of such plants, often being the chief place of food manufacture and 
storage, are nutritious as well; examples of this sort may be seen in 
jointfir (Ephedra), paloverde, ete. 
Plants with bland juices, such as are customary in the rose and 
mallow families, are, other things being equal, much more apt to be 
cropped by stock than are species belonging to families with an 
acrid, intensely bitter, or astringent sap, such as, for example, the 
buttercup (crowfoot), dogwood (cornel), or spurge families. There 
are, however, notable cases of bitter-tasting shrubs which are 
palatable to stock; for example, bitterbrush (Purshia) and cliffrose 
(Cowania). Both have decidedly bitter-tasting foliage, but both 
are highly palatable and important browse plants; it is noteworthy, 
however, that the two genera mentioned belong to the rose family, 
a group which, in view of its immense size, is singularly free from 
poisonous properties. 
Although, within rather narrow limits, taste gives us a certain 
clue to what is palatable or unpalatable to livestock, it is evident 
that there are chemical distinctions in bitterness, somewhat ill de- 
fined or not distinguished at all by the human palate, that register 
very definitely with browsing animals, causing them to reject some 
types of bitterness, while apparently relishing others. 
The distinctly saline taste exhibited by many shrubby plants, 
especially of the goosefoot family, growing in alkaline or saline 
situations, is in general agreeable to stock. Herbage of pronounced 
acidulous flavor appears to be seldom relished by grazing animals. 
It is very doubtful also whether any western shrub with a milky 
juice is palatable to livestock. 
The presence of disease, such as rusts, is another factor which 
affects the value of forage, often greatly reducing the palatability 
and quantity of the herbage produced, and sometimes causing sick- 
ness and losses. 
IMPORTANT WESTERN BROWSE FAMILIES, GENERA, 
AND SPECIES 
A truly excellent browse species may be said to have the following 
characteristics: 
High palatability and nutritiousness. 
Abundance on the range. 
Wide distribution. 
Height (within the reach of livestock). 
Abundance of herbage. 
Ability to withstand grazing (size and extent of root system; vigor and 
aggressiveness, ete.). 
Reproductive power, sexual and vegetative. 
Freedom from spines, awns, burs, or other anatomical processes injurious 
or annoying to grazing animals, or impairing the value of the animals’ wool, 
mohair, or pelt. 
The browse crop on western ranges is largely produced by about 24 
plant families and 60 genera, although at least half of the total num- 
ber of shrubby species are of appreciable browse importance there. 
At least 6 families and 17 genera are poisonous. The families, 
genera, and species noted in this publication are selected on the 
