Betula nigra Betula nigra Betula nigra, the black birch, river birch or water birch, is a species of birch native to the Eastern United States from New Hampshire west to southern Minnesota, and south to northern Florida and west to Texas. It is one of the few heat-tolerant birches in a family of mostly cold-weather trees which do not thrive in USDA Zone 6 and up. "B. nigra" commonly occurs in floodplains and swamps. "Betula nigra" is a deciduous tree growing to with a trunk in diameter. The base of the tree is often divided into multiple slender trunks. Bark Bark characteristics
Betula lenta male catkins pendulous, the female catkins erect. The fruit, maturing in fall, is composed of numerous tiny winged seeds packed between the catkin bracts. Seed production mainly occurs in trees that are between 40 and 200 years old, although light crops may occur as early as 15 years and as long as the tree lives. Contrary to common knowledge, the lifespan of "B. lenta" is typically around 200 years, and many individuals will reach 250 and even 300 years. The oldest known "B. lenta" has been confirmed to be 368 years old, and the species may live even longer than