Black Cottonwood, Populus tricocarpa
© 2000 J. Agee
Black cottonwood grows quickly to heights of 80 to 125 feet—up to 200 feet in bygone days, along the lower Columbia River—and diameters up to four feet or more. The men of the Corps of Discovery probably carved twelve of the seventeen dugout canoes they made en route from either black cottonwood or plains cottonwood.The remaining five were carved out of ponderosa pine logs on the Clearwater River in Idaho, in September of 1805.1
The leaf bud pictured at left is the feature containing a sticky black substance that gives the black cottonwood its proper botanical name. Balsam is "any of several aromatic resins . . . that contain considerable amounts of benzoic acid, cinnamic acid, or both, or their esters."2
Regrettably, interactivity on the World Wide Web is confined to the provinces of sight, sound, and the imagination, and there is no imaginable way in which the heady essence of Populus balsamifera can be conveyed in ones and zeros. For the present, at least, you have to be there.
1. Black cottonwood weighs 23.5 pounds per cubic foot. Assuming a canoe carved from a 30-foot black cottonwood log 40 inches in diameter, with a hull averaging four inches in thickness, and allowing for a little tapering at the bow and stern, approximately how much would the dugout weigh, empty? The hard, strong, fine-grained ponderosa pine wood weighs 29.5 pounds per cubic foot. Given boats of identical size, how much more weight did the men have to lug around the Great Falls of the Columbia than around the Great Falls of the Missouri, per canoe?
2. American Heritage Dictionary of the English Language, Third Edition.