The Black Cottonwood is a fast growing, broad-leafed tree that is commonly found along the Tualatin River. It can be identified by its large heart-shaped leaves with fine teeth and dark gray, deeply furrowed bark. Their light green leaves turn yellow in autumn. Each Black Cottonwood tree has either all male or all female flowers in the form of short clusters called catkins. They can grow up to 150 feet and 20 feet in circumference and live up to 200 years. Black Cottonwood is used to make coarse lumber and paper. Native people used the resin from Black Cottonwoods as medicine particularly for respiratory ailments.
