176 SILVA OF NORTH AMERICA. SALICACEE. 
and a half to two inches long and a third of an inch thick, with slender glabrous stems, and the pistillate 
are loosely flowered and from two and a half to three inches in length, with stout hoary tomentose 
stems; their scales are dilated at the apex, which is irregularly cut into numerous filiform lobes, and 
glabrous or slightly puberulous on the outer surface, and fall before the ripening of the fruit. The 
stamens, from forty to sixty in number, are inserted on a broad slightly oblique glabrous disk, and are 
composed of slender elongated filaments longer than the large light purple anthers. The ovary is 
subglobose, coated with thick hoary tomentum, crowned by three nearly sessile broadly dilated deeply 
lobed stigmas, and inclosed at the base in a thick deep cup-shaped glabrous membranaceous disk with an 
irregularly crenate or nearly entire revolute margin persistent under the fruit. When the capsule ripens 
the leaves are almost fully grown and the pistillate aments are from four to five inches in length; the 
capsule is subglobose, nearly sessile, pubescent or rarely almost glabrous, rather thick-walled, and three- 
valved. The seed is obovate, apiculate at the gradually narrowed apex, light brown, puberulous toward 
both ends, one twelfth of an inch long, and furnished with a tuft of long lustrous white hairs. 
Populus trichocarpa forms open groves by the banks of streams, and is distributed from southern 
Alaska’ southward through western British Columbia, where it extends eastward to the valley of the 
Columbia River,? through western Washington and Oregon, and along the mountain ranges and 
islands * of western California to the southern slope of the San Bernardino Mountains.* In the valley 
of the lower Stikeen River and southward through all the coast region to northern California, it 
grows to its largest size not far above the level of the sea; farther south.and beyond the influence 
of the ocean it is smaller, often not more than thirty or forty feet tall, and ascends into mountain 
canons, frequently reaching elevations of six thousand feet on the western slopes of the Sierra Nevada 
of central California; in western British Columbia, Washington, and Oregon it abounds in all the 
river-valleys and is the largest of the broad-leaved trees. 
The wood of Populus trichocarpa is light, soft, and not strong, although rather close-grained ; it 
contains thin hardly distinguishable medullary rays and minute open scattered ducts, and is light dull 
brown, with thin nearly white sapwood. The specific gravity of the absolutely dry wood is 0.3814, a 
cubic foot weighing 23.77 pounds. In Oregon and Washington, where the demand for the wood has 
already caused the destruction of most of the old trees, it has been largely made into the staves of 
sugar-barrels ; and it is also used in the manufacture of wooden-ware, bowls, and butter-tubs, although 
its bitter taste lessens its value for these purposes, and by the Indians of British Columbia in the 
building of canoes.° 
The soft pliable tough roots were formerly used by the Indians of Oregon and northern California 
in the manufacture of hats and baskets.°® 
The earliest account of Populus trichocarpa appears in the journal of Lewis and Clark for 
March 26, 1806, where the Cottonwoods growing near the mouth of the Columbia River are mentioned.’ 
The tallest and one of the largest of all Poplars, Populus trichocarpa, is conspicuous throughout 
the fluvial regions of the northwest coast, while it enlivens the coniferous forest of the California 
Sierra Nevada with the brilliancy of its pale stems and the fluttering of its beautiful lustrous leaves. 
1 The extreme northern range of Populus trichocarpa is still ® Greene, Bull. Cal. Acad. Sci. ii. 412.— Brandegee, Proc. Cal. 
undetermined. In 1887 Dr. G. M. Dawson, while exploring the Acad. Sci. ser. 2, i. 216 (Fl. Santa Barbara Islands). | 
region between 56° 30’ and 60° north latitude and 128° and 138° 4S. B. Parish, Zoé, iv. 348. 
west longitude, found it on the lower Stikeen River, and in the 5 G. M. Dawson, Can. Nat. n. ser. ix. 331. 
drier region east of the coast ranges, associated with Populus ° Havard, Garden and Forest, iii. 620. 
balsamifera of the east, and a Poplar, probably of the same species, " A History of the Expedition under Command of Lewis and Clark, 
on the Pelly and Lewis branches of the Yukon River. (SeeG.M. ed. Coues, iii. 908. 
Dawson, Garden and Forest, i. 58.) 8 Garden and Forest, v. 277, f. 52. 
2 Macoun, Cat. Can. Pl. 457. 
