Silver Poplar, Silverleaf Poplar, White Poplar: Populus alba (Synonyms: Populus alba var. bolleana, Populus alba var. pyramidalis)
Mountain Cottonwood, Narrowleaf Cottonwood, Narrowleaved Cottonwood: Populus angustifolia (Synonym: Populus fortissima) ?
Eastern Cottonwood, Necklace Poplar, Plains Cottonwood: Populus deltoides ssp. monilifera (Synonym: Populus deltoides var. occidentalis)
Black Poplar, Lombardy Poplar: Populus nigra (Synonyms: Populus dilatata, Populus italica, Populus nigra var. italica)
Quaking Aspen: Populus tremuloides (Synonyms: Populus tremula ssp. tremuloides, Populus tremuloides var. vancouveriana)
Balsam Poplar, Black Cottonwood: Populus trichocarpa (Synonym: Populus balsamifera, Populus balsamifera ssp. trichocarpa)