Black Cottonwood
Populus trichocarpa
Synonyms: Populus balsamifera ssp. trichocarpa, Populus trichocarpa var. ingrata

Close-ups of the upper and lower leaf surfaces of black cottonwood. Note the glaucous cast to the lower leaves which help identify this from the similar balsam poplar.

A young black cottonwood in a clearing.
Paul Slichter