Black walnut

Scientific name: Juglans nigra

Family: Juglandaceae (Walnut family)

A large deciduous tree found throughout the state, black walnuts are arguably Ohio’s most valuable hardwood tree. Its fine-grained, chocolate-brown, relatively lightweight wood is the ultimate choice for making solid wood furniture, interior trim, gunstocks, and high-quality veneer. The large nut contained beneath the husks of black walnut is enjoyed by humans as well as woodpeckers, foxes, and squirrels. This native tree prefers deep, moist, rich soils under sunny conditions and is deeply taprooted, making transplanting difficult. Aside from leaf spot, black walnuts are virtually disease and pest-free. Black walnut produces a chemical toxic to some plants and can poison nearby competition.

Identification

LEAF: Leaves alternate, pinnately compound, and range from 12-24 inches long with 11-23 sharply oval, toothed, long-pointed leaflets. The terminal leaflet at the end of the long leaf is frequently long or absent and the leaves have a strong, distinct odor when rubbed or bruised.

TWIGS AND BUDS: Twigs are stout and orange-brown to dark brown with a chambered pith and prominent terminal buds. Buds are gray and downy and leaf scars are large and hairless.

FRUIT OR SEED: Globular inner kernels or nuts are surrounded by a hard, round shell composed of two fused halves. The shell and fruit are surrounded by a thick outer husk that is yellow-green when immature and yellow-black when ripe. The dark-colored dye can seep from ripe fruits and easily stain skin and clothing.

BARK: Bark color ranges from brown-gray to gray-black, with a chocolate brown color underneath when scraped, flaky when young but ridged and furrowed with age. Narrow bark ridges form an interlacing diamondback pattern and develop thick, warty plates.

SHAPE: Upright rounded

MATURE HEIGHT: 60-85 feet.

Photo credits: ©Arthur Haines (Native Plant Trust), John Lynch (© 2024 Native Plant Trust)