IMPORTANT EANGE 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 (Ceanothus 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 



