Alnus rubra
The scientific name of Smooth Alder is "Alnus serrulata" (Aiton) Willd., synonymous with "Alnus noveboracensis" Britton, "Alnus rubra" Desfontaines ex Spach, "Alnus rugosa" (Du Roi) Sprengel, "Alnus rugosa" (Du Roi) Sprengel var. "serrulata" (W. Aiton) H. Winkler, "Alnus serrulata" (W. Aiton) Willdenow var. "subelliptica" Fernald, and "Betula serrulata" W. Aiton.