IMPORTANT WESTERN BROWSE PLANTS 167 
erally called sage(brush). The names wormwood and mugwort (cor- 
ruption of midgewort) are also sometimes applied to these plants 
in this country, as well as abroad. Several Old World artemisias 
are of economic interest, and a considerable number of them have 
become naturalized or adventive in parts of the United States. 
Big sagebrush (Artemisia tridentata), which ranges from western 
Nebraska to Montana, British Columbia, eastern California, and 
northern New Mexico, has a wider distribution than most American 
shrubs and is probably more abundant than any other. The species 
(fig. 42) is a stout bush, 1 to 15 feet high, with somewhat silvery, 
narrowly wedge-shaped leaves having usually three triangular teeth 
at the apex. While found on mountain peaks and high ridges, big 
sagebrush is essentially a dry-plains plant, where often for great 
distances it is the chief feature of the landscape. Coville (27), for 
example, estimates that it composes “ probably nine-tenths of the 
shrubby vegetation of the plains of southeastern Oregon,” and this 
estimate doubtless applies fairly accurately to other portions of 
the Great Basin having similar ecological conditions. It is most 
commonly known simply as sage(brush): or common sage(brush). 
Other vernacular names include black sage, a name derived from 
the dark bark color of the older stems; Colorado sage(brush), and 
white sage(brush) referring to the pale leaves. 
The altitudinal range of this shrub is considerable, varying in 
Montana, for example, from 3,300 to 8,300 feet (106) and in Colo- 
rado and Utah from about 4,000 to 10,500 feet, but the great mesas 
or plains at medium elevation or somewhat lower, immediately be- 
low the main mountain slopes, are its chief habitat. It is found 
on all slopes and in a considerable variety of soils, often in those 
of limestone origin, but rather seldom in granitic soils, though oc- 
curring in igneous formations such as disintegrated lavas. This 
shrub, however, is markedly intolerant of salinity, both in soil and 
subsoil, as Shantz has pointed out (20, p. 234 and pl. 53), and it 
attains its most luxuriant growth on deep, rich, moist, alluvial 
ioams. 
This shrub is of great importance to the western stockman, 
covering as it does in abundant stand enormous stretches of readily 
‘accessible range. On the higher summer ranges big sagebrush is, 
where it occurs, seldom of any particular value. On the lower 
ranges, however, where it is most abundant and where its slender 
twigs, persistent large leaves, and the flowering or fruiting heads 
are available to livestock through the late fall, winter, and early 
spring, the species is often the mainstay ration and is particularly 
valued at such times for sheep and goats. Cattle browse on the 
plant considerably during this period, but less so than sheep; 
horses crop it to some extent. The typical open, rather scattered 
growth is conducive to optimum utilization, and few if any native 
western shrub species can surpass this plant in size of total forage 
crop produced. Livestock, especially sheep, are well known to 
acquire a “sage hunger,” often leaving other feed alone for several 
days until this craving is appeased. 
in general the forage value of big sagebrush increases toward the 
southern portion of its range, being usually poorly regarded in 
Washington and much of Oregon, and highly esteemed in Nevada, 
