Pseud otsuga 817 



conifers, which have a much more restricted distribution. In Montana it is associated 

 with the western larch : in California it encroaches on the redwood belt ; in south- 

 western Oregon it is mixed with the Lawson cypress ; while in the rest of the great 

 forest of this state, and of Washington and northern Idaho, Thuya plicata is usually 

 its constant companion. The various silver firs, hemlocks, and the Sitka spruce also 

 take part, in different localities, in the mixture of coniferous trees in the Douglas 

 forest. Towards the edges of the prairie regions and in the drier parts of the 

 mountains, the Douglas fir gradually gives place to Pinus ponderosa, which is the 

 characteristic tree of dry soils, where a very moderate rainfall prevails. 



The northern limit of the Douglas fir extends from near the head of the Skeena 

 River, latitude 54", in the coast range of British Columbia to Lake Tacla in the Rocky 

 Mountains, latitude 55", reaching its most easterly point near Calgary in Alberta. In 

 the coast range, the tree grows at some distance inland north of latitude 51" ; while 

 south of this line it is common on the coast of the mainland and in the island of 

 Vancouver ; and in this region, and in Washington and Oregon, between the western 

 foothills of the Cascades and the sea, it is most abundant and of its largest size. 

 It attains its maximum development, 300 feet in height, in Vancouver Island and 

 on the northern slopes of the Olympic Mountains in Washington, where the rainfall 

 is excessive ; whereas, on the Cascades and in the interior of the continent, it rarely 

 exceeds 150 feet in height. It is common, but only of moderate size, in the forests 

 of northern Idaho and of western Montana,^ ascending to 6000 feet. 



The Douglas fir extends southwards along the Rocky Mountains, in the 

 Yellowstone Park in Colorado, where it grows between 6000 and 11,000 feet 

 altitude ; in Utah, to the east of the Wasatch range ; in northern and central New 

 Mexico and northern Arizona, where it is common between 8200 and 9000 feet, 

 being rare and of small size in the southern parts of these two states, where it 

 ascends to 6000 or 7000 feet ; in the Guadalupe Mountains of western Texas, where 

 it is abundant ; and it spreads into Mexico, along the Sierra Madre range of 

 Chihuahua and the mountains of Nuevo Leon, reaching its most southerly point 

 near the city of San Luis Potosi. 



In California it extends southward in the coast mountains ^ as far as Punta Gorda 

 in Monterey county, but is not abundant, and is rarely over 150 feet in height; 

 inland it extends to the Sierra Nevada,^ where it grows to a large size and ascends 

 to 7000 feet. It does not occur in the arid tracts of Nevada and Utah, which lie 

 between the Sierra Nevada and the Wasatch ranges. (A. H.) 



So little seems to be known by British foresters as to the conditions under 

 which the tree grows in America, that though I quite agree with the preceding 

 account, it may be as well to add some of my personal experience of the tree as I saw 

 it on my last journey in 1904. In the Blackfoot valley of Montana it is associated 



' At Whitefish, Montana, an average tree, growing with the western larch, was 140 feet in height and 8 feet in girth, 

 and showed 245 annual rings ; the sapwood, | inch wide, containing 45 rings ; the bark was 2,\ inches in thickness. 



2 Jepson, in Flora Western Mid. California, ig (190 1) says that it is frequent in the Santa Cruz mountains; but is 

 not known in the Mt. Diabolo and Mt. Hamilton ranges, or in the Oakland hiUs. 



^ Sargent in Garden and Forest, x. 25 (1897), says that it does not extend in the Sierras, south of the head of King's 

 river, or within 100 miles of the territory occupied by P. macrocarpa. Jepson {op. cit. 20), makes its southern limit on the 

 Sierras, about the head-waters of Stevenson Creek, which is not far from the head of King's river. 



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