Black cottonwood (Populus trichocarpa) is the largest of the American poplars and the largest hardwood tree in western North America. The tree grows primarily on moist sites west of the Rocky Mountains. The most productive sites are the bottom lands of major streams and rivers west of the Cascade Range in the Pacific Northwest. Pure stands may form on alluvial soils. Black cottonwood is harvested and used for lumber, veneer, and fiber products. Many kinds of wildlife use the foliage, twigs, and buds for food, and the tree is planted for shade and in windbreaks and shelterbelts.
Black cottonwood has been planted as windbreaks and shelterbelts. The wood of black cottonwood is similar to that of other cottonwoods with light color, straight grain, fine, even texture, and is light in weight. It dries easily, is moderately stable in use, and, although not strong, is tough for its weight.
Black cottonwood has short, fine fibers and is used to produce pulp for high-grade book and magazine papers. The species peels easily, and its veneer is used as core and cross-banding stock in plywood and in baskets and crates. The light weight, good nailing characteristics, and light color of the lumber are ideal for manufacture of pallets, boxes, and crates.
Forestryimages.org provides several images of parts of black cottonwood. The tree is a hardwood and the lineal taxonomy is Magnoliopsida > Salicales > Salicaceae > Populus balsamifera trichocarpa (Torr. & Gray ex Hook). Black cottonwood is also sometimes called balsam cottonwood, western balsam poplar, and California poplar.
3. The Range of Black Cottonwood
The range of black cottonwood extends northeast from Kodiak Island along Cook Inlet to latitude 62° 30° N., then southeast in southeast Alaska and British Columbia to the forested areas of Washington and Oregon, to the mountains in southern California and northern Baja California (lat. 31° N.). It is also found inland, generally on the west side of the Rocky Mountains, in British Columbia, western Alberta, western Montana, and northern Idaho. Scattered small populations have been noted in southeastern Alberta, eastern Montana, western North Dakota, western Wyoming, Utah, and Nevada.
Leaf: Alternate, simple, deciduous; variable in size and shape on same tree, commonly 3 to 6 inches long, but can be much larger; ovate-lanceolate to deltoid, dark green above and silvery white below with rusty smears of resin, margins wavy to crenate; petiole long, and most often round but may be flattened.
Twig: Moderately stout, greenish brown to olive-gray, often ribbed or angled in cross section when young, covered with distinct lenticles, spur shoots are common on older branches; buds are long (1/2 to 3/4 inch) and sharp-pointed, resinous and aromatic, covered with imbricate scales. Twig has a bitter aspirin taste.
Black cottonwood sprouts from the lateral roots, root crown, and bole after top-kill by fire. It also establishes from seed.