IMPORTANT RANGE PLANTS. 43 
In the Canadian zone the flowers begin to unfold about June 20, and 
by July 20 most of them have expanded. The seed matures from 
about July 25 to August 15. In 1909 the seed crop from the Canadian 
zone germinated 29.5 per cent. Reproduction on the range in 
general is taking place slowly. 
Geranium is one of the choice forage plants for cattle and sheep. 
Since it grows in abundance on the cattle and sheep allotments, it is 
equally valuable to both classes of stock. When it is young all but 
the lower portion of the coarse stem is eaten, but later only the 
flowers, immature fruits, and leaves are grazed. About the time 
that the seed crop has matured the leaves dry up and the plant 
loses much of its forage value. 
FlREWEED. 
( Chamaenerion angustifolium. ) 
Chamaenerion angustifolium is given its name, fireweed, because of 
its prevalence on burned-over forest lands. This species is the most 
valuable perennial grazing plant of the evening primrose family. 
It attains a height of 2 to 5 feet, depending on the situation. The 
cylindrical stem bears an abundance of long, slender, nearly entire, 
thin leaves, and the inflorescence consists of a raceme of delicately 
pink or nearly white, or sometimes purple, flowers developed at the 
apex of the stem (Plate XLI). The long, slender capsules split into 
four divisions at maturity, liberating the numerous minute seeds 
provided with a tuft of long silky hairs, by means of which they are 
carried great distances by the wind. 
In the Wallowa National Forest fireweed is most abundant on 
burned-over areas in rather dry, often coarse, gravelly and even 
sterile soils in the Canadian zone. It also occurs in both of the con- 
tiguous zones, though never in pure stand. It is one of the first 
species to invade heavily burned lodgepole-pine forests. 
Fireweed is drought resistant, comparing hi this respect with some 
of the grasses which grow both in moist and in dry situations. The 
plants were found not to wilt excessively until the soil moisture was 
reduced to between 8.2 and 11.5 per cent, depending upon the par- 
ticular soil type. In the moister places, where decayed vegetable 
matter is more abundant, the moisture requirement figures are 
higher. 
The production of flower stalks, like the seed-maturing period, 
continues for an unusual time. In the warmer situations flowers 
begin to unfold as early as June 20, and in a few places buds are 
found at the apex of the raceme as late as the early part of August. 
'The lower flowers are first displayed, and as the season advances 
there is a gradual sequence or succession in the flowering toward the 
