CONIFERS. 



SILVA OF NORTH AMERICA. 



115 



the San Francisco Peaks of northern Arizona. On tte coast mountains o£ Alaska* it forms the timber- 

 line up to elevations of five thousand feet above the sea-level, growing almost habitually in the coast 

 region with Tsuga Mertensiana, and near the head of the Lewes River, in latitude 60"", descending to 

 the shores of Lake Bennett, where it is very abundant at elevations of two thousand one hundred and 

 fifty feet. In southern British Columbia, on the Selkirk Mountains, where it grows perhaps to its 

 largest size, Ahies lasiocarpa is scattered through dense forests composed principally of the western 

 Hemlock, the Patton Spruce, and the Engelmann Spruce, and in all the northern Eocky Mountain 

 region of the United States, where, north of Colorado, it is the only Fir-tree east of the continental 



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divide, it grows on wet subalpine slopes and plateaus near the timber-line, sometimes forming groves in 

 park-like openings of the forest, and with the Engelmann Spruce, at elevations of over eight thousand 

 feet above the sea, covers the bottoms of deep caiions with continuous forests } ^ on the Cascade and 

 Olympic Mountains it forms the timber-line with Tsuga Mertensiana on high wind-swept rocky ridges 

 at elevations of from four thousand to nearly eight thousand feet above the sea,^ and on the Blue and 

 Powder River Mountains and the other ranges in the interior of Washington and Oregon it grows with 

 the White Fir and the Lodge Pole Pine, and reaches the upper limits of tree-growth ; in Colorado it is 

 widely distributed, growing usually in the neighborhood of streams at elevations of between seven and 

 ten thousand feet above the sea, sometimes forming small groves, but more often scattered among 

 Aspens and Spruces, and occasionally ascending to eleven thousand feet above the sea.* On the San 

 Francisco Peaks it principally inhabits northern slopes between elevations of nine and ten thousand feet, 

 scattered singly or in small masses through the forests of Picea Engelman7ii and Pimis aristata.^ 



The wood of Abies lasiocarpa is very light, soft, and not strong nor durable ; it is pale brown or 

 nearly white, with lighter colored sapwood, and contains inconspicuous narrow bands of small summer 

 cells and numerous obscure medullary rays. The specific gravity of the absolutely dry wood is 0.3476, 

 a cubic foot weighing 21.66 pounds. It is probably little used except as fuel. 



Abies lasiocarpa was, no doubt, one of the Pine-trees which Lewis and Clark noticed in September, 

 1805, when they crossed the Bitter Root Mountains in their journey to the Pacific Ocean.^ Nothing 



^ " Near Telegraph Creek, a tributary of the Skeena River, in 

 about latitude 58° north on the east side of the coast mountains, 

 the Firs grow higher than other trees, dwarfing at a height of 

 about five thousand feet into low chaparral. This dwarfing seems 

 to he due as much to heavy snow as to altitude, for at the same 

 elevation on ridges where the snow can never be deep the dwarf 

 and erect forms grow close together. This Fir forms beautiful 

 chaparral, the flat thickly foliaged plumes, broad and fan-shaped, 

 being imbricated over each other by the pressure of the snow, so 

 that the high slopes seem to be neatly and handsomely thatched. 

 In this form it is seldom more than three feet high, yet the bushes 

 bear fertile cones and seem thrifty and happy as if everything were 

 to their mind. In this dwarfed form it reaches a height of five 

 thousand five hundred feet. At a height of four thousand feet the 

 trees are erect and more than fifty feet high and one foot in diameter 

 at the ground. The Pine and Spruce of the region lying between 

 the head of Dense Lake and Telegraph Creek in great part give 

 place to this handsome Fir around the lake, and upward to the 

 north and on the mountains, the tallest being about one hundred 



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feet high and one foot in diameter at the ground and feathered 

 with short branches from top to bottom. The cones, which are 

 three inches long and one inch in diameter, are dark purple, with 

 short dark-colored bracts and very dark seed-wings. The moun- 

 tain side and the slopes on the west side of the lake is forested 

 with this tree." (Muir in litt.) 



Ahies lasiocarpa^ which grows up to elevations of fully five 

 thousand feet at the head of the passes which cross the coast 



mountains in latitude 60°, probably grows much farther north on 

 the mountains of the valley of the Yukon River, although I have 

 not been able to find any record of its existence on these mountains, 

 which are still very imperfectly explored. 



It is stated by Dr. George M. Dawson, the director of the Geo- 

 logical Survey of Canada, that AUes lasiocarpa crosses the Rocky 

 Moimtains into the Peace River region, and grows in cold, damp 

 situations in the country between Lesser Slave Lake and the Atha- 

 basca River {Can. Nat n. ser. ix, 326. See, also, Macoun, Cat. 

 Can. PL 474). I have not been able to see specimens, however, 

 from any point east of the Rocky Mountains. 



2 Tweedy, Ft. Yellowstone National Parlz^ 11, 74. 



s On Mt. Rainier, in Washington, the highest of the volcanic 

 peaks of the Cascade Range, Abies lasiocarpa grows from four 

 thousand five hundred feet to the extreme upper limits of tree- 

 growth, which is at nearly eight thousand feet. At its lowest 

 levels it grows with Abies nohilis and Abies amaUlis ; leaving them 

 between five and six thousand feet, it attains its best size two 

 thousand feet higher, its associate at high elevations being always 

 Tsuga Mertensiana ; above seven thousand feet it clings close to 

 the ground with semiprostrate stems forming great mats of thick 

 branches which, with dwarf plants of the Mountain Hemlock and 

 Pinus albicaulis, cover the most exposed ridges. 



* Brandegee, Bot. Gazette, iii. 33. 



s Merriam, North American Fauna, No. 3, 120, 



6 History of the Expedition wider Command of Lewis and Clark, 

 ed. Coues, ii. 598. See, also, Sargent, Garden and Forest, x. 29. 



