Black cottonwood, Populas balsamifera, is a species variation of cottonwood that grows from the western tip of Canada down to Montana and through part of Texas. The specific name balsamifera comes from the buds which have a resinous substance which resembles coniferous resin sap.
Here’s what’s fun – the Spanish word for cottonwoods is a lamo and from that we think that the Alamo in Texas got its name and the Los Alamos nuclear facility has that derivation, too. Our eastern cottonwood, Populus deltoides, overlaps in some areas with black cottonwood but predominantes in our part of the country. Its specific name deltoides refers to the triangular shaped leaf of eastern cottonwood, which also has a flattened petiole that causes the leaves to flutter in the slightest breeze. Both are fast growing trees and good for wildlife and reclamation projects.