16 MISC. PUBLICATION 101, U. S. DEPT. OF AGRICULTURE 
relatively large and persistent foliage, Scouler willow is one of the 
best, if not the best, of the native western range willows for browse. 
Its broad soil requirements and rapid invasion of burns make it 
especially valuable, and it doubtless is often a useful nurse crop for 
conifer reproduction. Although it occasionally occurs in almost im- 
penetrable thickets, its usual growth is in frequent, scattered, broad, 
and relatively low clumps—an ideal browse formation readily ac- 
cessible to stock. Because of its form of growth and its common oc- 
currence on the gravelly rocky slopes of high and medium eleva- 
tion where sheep are wont to abound in late spring, summer, and 
fall, Scouler willow is one of the best of all Salices for sheep. In 
a very few places, it is true, Scouler willow is seldom if ever grazed, 
so far as is known, doubtless owing to peculiar local conditions; but 
in general its palatability to both sheep and cattle is high, both 
foliage and twigs being consumed. Sampson (7/0) regards Scouler 
willow as the most important species on burns in the Wallowa Moun- 
tains of northeastern Oregon and comments as follows on its graz- 
ing value there: 
The time at which the leaves are developed renders it valuable as an early 
browsing plant. As high as sheep can reach, the branches are stripped of 
their leaves, though the bark is seldom eaten. * * * The more sheep browse 
on the willow the denser becomes the growth. This is due to the vigorous 
and persistent sprouting of new branches as a result of the trimming back of 
the young shoots through grazing. Even when a bush is cut to the ground a 
number of young shoots are produced. 
OTHER SPECIES 
One of the commonest and most widely distributed dwarf willows 
is Bebb or beak willow (Saliva bebbiana), a rather large shrub or 
small tree which is generaily held in high esteem whether on cattle, 
sheep, or goat range. Other common shrub-to-small-tree willows 
that are relished by livestock are narrowleaf willow (S. éxigua) ; 
Geyer willow (S. geyeriana); blueback willow (S. glaucops), an 
important species of the highest summer ranges; and blue willow 
(S. subcoerulea). Five important essentially shrubby western wil- 
lows are undergreen willow (S. commutata) of the Northwest (con- 
sidered one of the most important sheep browses in portions of 
central Oregon and elswhere) ; Idaho willow (S. wolf tdahoensis), 
a very good sheep browse in Idaho; Barclay willow (S. barclay?), 
especially esteemed for sheep; greensides willow (S. monochroma) 
of the Northwest (reaching southeast to Colorado), with thin, rela- 
tively broad leaves, dark green on both sides; and silverleaf willow 
‘(S. argophylla) of value for both cattle and sheep. Greensides 
willow is claimed by local observers to be the most palatable member 
of the genus in western Washington and most palatable in August 
and September. Among the dwarf high-alpine willows may be 
noted tufted willow (S. caespitosa) and summit willow (S. saximon- 
tana), sometimes called Rocky Mountain willow, too small to have 
much grazing significance but furnishing a few nibbles for sheep 
in summer, where other vegetation is none too abundant. 
ASPEN, POPLARS, AND COTTONWOODS (POPULUS SPP.) 
About 15 species and 8 subspecies or varieties of the genus Populus 
are native on western ranges. Of these trees, all of which furnish 
