FOREST TREES OF THE PACIFIC SLOPE. 101 



situations appear to have rougher and harder bark than those in the moist, 

 deep forest. Trees of the high, very dry interior mountain slopes, particularly 

 young trees, may have soft, cork-like, gray-brown bark. (This may well be a 

 result of the excessively dry atmosphere, for one or two firs of that region have 

 similar hark). Otherwise these trees are not different from those with the 

 ordinary hark. .Mature foliage is usually dee], yellow-green. In the drier parts 

 of its range Douglas fir sometimes has blue-green foliage of varying shades, 

 especially in Rocky .Mountain forms. This color is particularly pronounced 

 during the early maturity of the leaves. Foliage of a season's growth remains 

 on the tree aboul eight years, when it is shed at irregular intervals. The leaves 

 (fig. ."><>) are flat, slightly grooved above and commonly blunt, or very occa- 

 sionally pointed. Cones ripen early in August and by September they begin 

 to open and shed their seed. A few weeks later the cones drop from the trees. 

 The cones (fig. 36), which are cinnamon or reddish-brown, furnish easy and 

 reliable means of identifying this tree. Their simplest distinction is the 3- 

 pointed. trident-like thin bracts protruding from among the cone-scales. Cones 

 vary from li to 4£ inches in length, but they are commonly about 2i to 3 

 inches. The seeds (fig. 36, a) are dull russet-brown, with areas of white. 

 Seed-leaves, about three-fourths of an inch long, are 6 to 7. Wood varies 

 widely in character and grain, which may be very carse. medium, or fine. 

 Coarse-grained wood is usually distinctly reddish-brown, the "red fir" of lum- 

 bermen. Fine-grained wood is a clear yellowish brown, the "•yellow fir" and 

 "Oregon pine" of lumbermen. The botanical characters of trees furnishing 

 these dissimilar qualities of wood are the same, and there is no foundation for 

 the popular belief that these woods come from two different "varieties" or 

 "species" of trees; indeed the two grades of wood may sometimes be obtained 

 from the same Tree. *For the first stage of from o<» to 100 or more years 

 diameter growth is rapid, giving coarse-grained wood, while the later stages 

 Of growth are. as a rule, slower and give fine-grained wood. The invariable 

 difference in color between these two grades of wood is often attributed to the 

 character of the soil, but this explanation ignores the fact that both grades 

 may come from the same tree. The true explanation is yet to be found. Grades 

 intermediate between these are also common, especially in trees grown outside 

 of the humid northwestern range, from which the bulk of "red" and "yellow" 

 timber is derived. Both grades are exceedingly important commercially, but 

 the finer-grained, yellow wood is now being worked up for the finest grades of 

 finishing lumber, for which it competes with high-class pine. 



Longevity. — Long-lived. Trees from .', to 4 feet in diameter are from 1.">0 

 to 200 years old, while those from 4 to 8 feet in diameter are from 2(H) to 375 

 years old. One tree 9 feet through showed an age of h.".-"> years. The ages of 

 rare trees larger than this are probably from 400 to ."><»!> years. 



KANGE. 



Western North America from British Columbia southward to central California, to 

 northwestern Texas. Bouthern New Mexico. Arizona, and northern Mexico. 



BRITISH COLUMBIA. — From east side of Rocky Mountains westward to Pacific coasl 

 and northward to TaHa Lake Mat. 55° 10') and Skeena River (lat. 54° 20') ; in south- 

 ern part, from sea-level to ' 6,000 feet; farther north, at general elevation of country, 

 hut absent from valleys of southern part of central plateau, as also from higher parts 

 of Rocky, Gold, and Selkirk Mountains. From Rocky Mountains eastward to Calgary 

 and Porcupine Hills: northward to head of Athahaska and Grand Pork Fraser rivers, 

 hut absenl from Cariboo Range; northward in Fraser River Valley to McLeods, Tacla, 

 Babine, and Francois lakes : absent from headwaters of Salmon River, but on coast 

 range northward to Skeena River. Northward on Pacific coasl only as far as north end 

 of Vancouver Island, not on coast archipelago, and rare on west coast of Vancouver 

 Island. 



