IMPORTANT WESTERN BROWSE PLANTS 163 
Bue fall, winter, and early spring, and limitedly browsed by 
cattle. 
Low rabbit brush (C. viscidiflorus pumilus, syns. C. pumilus, 
Bigelovia douglasii pumila) one of the smallest members of the 
genus, occurs abundantly on dry hills and plains of medium eleva- 
tion in Colorado and Utah and northward and westward to Oregon 
and Montana. It is considered fair browse in northern Utah and 
southern Idaho in the fall, both cattle and sheep cropping the 
flower stalks and leaves. 
Sawtooth rabbit brush (C. viscidiflorus serrulatus, syns. 0. glau- 
cus, C. serrulatus, Bigelovia douglasii serrulata) has a more eastern 
range than typical forms of the species, occurring from Wyoming 
to New Mexico and Arizona. It is found on dry plains and slopes 
at 5,000 to 10,000 feet and Nelson (25) indicates that it never grows in 
soils containing alkali. It is considered fair browse for both cattle 
and sheep in spring and fall. 
Twistleaf rabbit brush (C. viscidiflorus tortifolius, syns. C. torti- 
folius, Bigelovia douglasii tortifolia), easily recognized by its con- 
torted leaves, is found in about the same ‘sites as typical forms of 
the species. In the Uinta Mountains it is commonly held to be fair 
browse for both sheep and cattle after frost, and in southwestern 
Utah and the Kaibab Plateau the tops are said to be cropped by 
cattle to a rather considerable extent. 
SNAKEWEEDS (GUTIERREZIA SPP.) 
Gutierrezia, whose species are frequently known as broomweed, 
brownweed, matchweed, turpentine-weed, yellow-top, yellow weed, 
and yerba de vibora, is a New World genus of about 25 species. Ten 
of the species occur in the United States, all in the West; some of 
them are herbs, but most are either shrubs or half shrubs with woody 
roots, crowns, and stem bases. 
Broom snakeweed (G. sarothrae, syns. G. diversifolia, euthamiae, 
linearis, longifolia, and tenuis), by far the commonest and most 
abundant of these species, ranges from Manitoba to western 
Nebraska, Kansas, and Texas, southern California, and Idaho, occur- 
ring chiefly on well-drained loamy soils in open weed areas at 4,000 
to 7,000 feet. This small undershrub is usually considered worthless 
as forage and, when abundant, as an indicator of overgrazing, but 
on some areas (notably in Utah and eastern Nevada) it is reputed 
to be fair browse for cattle and horses in spring and fall, presumably 
because there is little, if any, better feed available. It seems evident 
that extensive browsing of this plant is not without serious conse- 
quences. Stockmen on the Sitgreaves National Forest, Ariz., state 
that this species poisons sheep and horses, affecting their kidneys. 
Broom snakeweed often comes in heavily after prolonged drought. 
. It is sometimes killed by certain borers and other insects, and in 
1924 H. S. Barber and W. S. Fisher, of the Bureau of Entomology, 
identified certain snakeweed-killing insects submitted from the 
Jornada Range Reserve, southern New Mexico, as belonging to 
the genera Crossidius, Diplotaxis, and Mecas. It is possible that 
to a certain extent artificial control of this range vegetative pest 
through such insects may some day be practicable. 
