Flower: Preformed aments, male near the end of the twig, 2 to 3 inches long. Female catkins upright, 1/4 to 1/2 inch long. Flowering in early spring.
Fruit: Cone like, 1 to 1 1/2 inches long, with many hairy scales, containing tiny, 3-winged seeds.
Twig: Slender, orangish-brown in color, smooth or slightly pubescent, with the terminal bud absent. Lateral buds may be slightly pubescent. No wintergreen odor
when cut.
Bark: Smooth on young trees, salmon to rust colored. On older trees, developing papery scales, exfoliating horizontally with several colors (creamy to
orangish-brown) visible. Later developing coarse scales.
Form: River birch is a medium-size tree with poor form. The trunk generally divides low into several arching branches.
