IMPORTANT RANGE PLANTS. 41 
Fire willow rarely develops into tree form in the region studied, 
though elsewhere it often attains a height of from 15 to 25 feet and a 
diameter of 8 inches. The leaves are of a light shade beneath, smooth, 
and free from hairs on the upper surface. The midrib is prominent 
and yellow (Plate XXXVIII). 
This willow grows along mountain streams, in canyons, and on 
gentle slopes in damp leaf litter or rather poorly disintegrated soils. 
While it is sometimes sparsely scattered it more often grows in dense 
clumps. On burned-over areas in canyons and on gentle slopes 
where the soil has not been rendered sterile, it often produces dense 
low thickets. On the Wallowa National Forest where it grows in 
close association with snow bush or buck brush (CeanotJius velutinus) 
in the Canadian zone, it forms what is known as chaparral. In the 
Hudsonian zone it occurs more sparingly. 
Male and female flowers are borne on different bushes, the seed 
production, of course, being confined to the female ones. The seeds 
ripen in the spring about the time the leaves have reached full 
development. The little pods open up soon after maturity and 
liberate the silky hairy seeds, which are widely distributed. 
No tests were made of the viability of the seed of this species. It 
produces an abundance of seed, but reproduction is mainly vegetative. 
In the Wallowa Mountains fire willow is the preeminent browsing 
plant. The low and spreading habit of growth adds greatly to its 
value as a sheep forage, and 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. Since this plant makes a comparatively rapid growth, 
a portion of the branches are soon beyond the reach of sheep and 
injury from severe grazing is unusual. In fact, 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. 
Wild Buckwheat. 
{Polygonum phytolaccaefolium. ) 
This plant belongs to the well-known buckwheat family; the genus 
is represented by some 70 species in the United States. 
Wild buckwheat is a perennial with a coarse, fleshy, sparsely 
branched but deep root. It attains a height of about 2 feet; the 
stem is well supplied with comparatively large, oval-shaped leaves, 
and panicles of rather small greenish white flowers (Plate XXXIX). 
The species is mainly confined to exposed situations in the Hud- 
sonian zone, though it occurs to a limited extent in both of the 
bordering zones. It attains its best development on mountain 
85154°— Bull. 545—17 6 
