River Birch (Betula nigra)

USDA NRCS. Wetland flora: Field office illustrated guide to plant species. USDA Natural Resources Conservation Service. Provided by NRCS National Wetland Team, Fort Worth, TX. 
 
Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 1: 609. Courtesy of Kentucky Native Plant Society.