88 



SILVA OF NOBTH AMERICA 



CONIFEE^, 



Picea (Pseudotsuga) Douglasii, Bertrand, -4w?^. jS^a. Nat, Pseudotsuga Douglasii, var. glauca, Mayr, Wald. Nord- 



s^r. 5, XX. 87 (1874), 



aw. 307, t. 6, f. (1890). 



Pseudotsuga taxifolia, Britton, Trans. N, T. Acad. ScL Tsuga taxifolia, Otto Kuntze, i^ez;. Gen. PL ii. 802 (1891). 

 viii. 74 (1889). — Lemmon, Bep. California State Board Pseudotsuga taxifolia, var. suberosa, Lemmon, Erythea, 



Forestry, iii. 130, t. 10, 11 {Cone-Bearers of California) ; 

 West - American Cone-Bearers, 56, t. 9 ; Bull. Sierra 

 Club,{i. 161 (Conifers of the Pacific Slope). 

 ContriL U. S. Nat. Herb. v. 50. 



i. 48 (1893) ; West-American Cone-Bearers, 57 ; Bidl. 

 Sierra Club, li. 161 {Conifers of the Pacific Slope). 



4 



Leiberg, Pseudotsuga taxifolia, var. elongata, Lemmon, Erythea, 



i. 49 (1893). 



A tree, when grown under favorable conditions often two hundred feet in height, with a trunk 

 three or four feet in diameter, and frequently much taller,-^ with a trunk ten or twelve feet in diameter; 

 or in the dry interior of the continent rarely more than eighty or one hundred feet high, with a trunk 

 two or three feet thick, and at high elevations occasionally reduced to a low shrub.^ The slender 

 crowded limbs, which are densely clothed with long pendulous lateral branches, are horizontal or more 

 or less pendulous below, and erect above ; when the tree is young and has grown in an open situation 

 they form a narrow open handsome pyramid with its base resting on the ground, but when the Douglas 

 Spruce is crowded in the forest its trunk, decreasing but slightly in diameter often for a hundred feet 

 above the ground, is generally deprived of its branches for two thirds of its length and is surmounted 

 by a comparatively small narrow head which on very old trees sometimes becomes flat-topped by the 

 lengthening of the upper branches. On young trees the bark is smooth, thin, rather lustrous, and 

 dark gray-brown ; beginning to thicken early near the ground and to divide into oblong plates, it 

 ultimately separates into great broad rounded and irregularly connected ridges which are broken on 

 the surface into small thick closely appressed dark red-brown scales, and, usually from ten to twelve 

 inches in thickness on old trees, it is occasionally two feet thick near their base ; ^ or sometimes in arid 

 regions the bark is paler colored and soft and spongy.* The winter-buds are ovate and acute, with thin 

 scales rounded, entire, or occasionally slightly erose or denticulate on the margins, the terminal bud 

 being often a quarter of an inch in length and nearly twice as large as the lateral buds. The branchlets 

 are covered for three or four years with fine pubescence, and during their first season are pale orange- 

 color and lustrous; turning rather bright reddish brown in the autumn, they gradually grow dark 

 gray-brown after their second summer. The leaves are straight or rarely slightly incurved, rounded and 

 obtuse at the apex, or on leading shoots and rarely on lower sterile branches acute, with short slender 

 callous tips, from three quarters of an inch to an inch and a quarter long, from one sixteenth to one 

 twelfth of an inch wide, light yellow when they first emerge from the bud, and dark yellow-green or 



^ I have not been able to obtain any reliable information con- 

 cerning the maximum height of the Douglas Spruce. Lumbermen 

 on Puget Sound habitually speak of trees from three hundred to 

 three hundred and fifty feet tall, but their statements, unsupported 

 by actual measurements, must be accepted cautiously. It is not 

 impossible, however, that this tree may grow to even ia greater 

 height than three hundred and fifty feet, as large specimens in 

 some of the sheltered valleys at the base of the Olympic Moun- 

 tains of northwestern Washington tower far above the surrounding 

 forest, which undoubtedly has an average height of nearly three 

 hundred feet. 



In this region and on the western slopes of Mt. Rainier in VSTash- 

 ington, trunks from ten to eleven feet in diameter five feet above 

 the surface of the ground and free of branches for two hundred or 

 two hundred and fifty feet are not rare, two or three such trees 

 sometimes standing on an acre of ground. Individuals twelve feet 

 in diameter may occasionally be seen, although they are very rare, 

 and lumbermen and prospectors tell of trees with trunks sixteen 

 feet in diameter. The trunks of Picea Sitchensis, Thuya plicata, and 

 of Taxodium mucronatum of Mexico are larger at the ground than 



those of Pseudotsuga mucronata, but they taper rapidly and soon 

 lose their great girth, while the trunk of the Douglas Spruce car- 

 ries its size to an immense height with a hardly perceptible reduction 

 of diameter, and no other tree of the continent, excepting the two 

 Sequoias, equals it in massiveness of trunk or in productiveness of 

 timber. (See Garden and Forest, x. 292, f. 38.) 



^ In 1883 I found at an elevation of six thousand feet above the 

 level of the sea, at the head of the Cutbank River, on the eastern 

 side of one of the northern passes over the continental divide in 

 Montana, a Douglas Spruce only eighteen inches in height but 

 covered with cones of full average size. 



3 The thickest specimen of the bark of Pseudotsuga mucronata 

 which I have seen was in Seattle, Washington, and was twenty- 

 six inches in thickness. 



^ Upon the soft spongy character of the bark of the Douglas 

 Spruce on the San Francisco Peaks in northern Arizona and on 

 some of the mountain ranges of northern New Mexico, Lemmon 

 based his variety suberosa {Erythea, i. 48). On the San Francisco 

 Peaks AUes cmcolor and Abies lasiocarpa have also soft spongy 

 bark, which is probably the result of peculiar climatic conditions. 



