Black Walnut

Juglans nigra

Black Walnut 

Arguably among the most commercially useful native trees found along the Cahaba River Tree Trail, the black walnut is considered an important source of both lumber and food. Some well-known uses of its deep brown wood are gunstocks – particularly for rifles – and veneer. Its wood is also used to make furniture, flooring, paddles, coffins and more. A yellowish-brown to brownish-black dye made from its drupes was used by early American settlers as hair dye, and is still useful today for things like ink and wood staining. The seed of the black walnut is a popular edible nut for both wildlife and humans, being shelled commercially in the United States, though it is more difficult to extract from its exceptionally hard shell than the European walnut. Those hard shells have a purpose of their own, however, being crushed and used for slip-resistance in automobile tires and as an abrasive in things like sandblasters and jet engine cleaners. 

The following identification information is from Trees of Alabama, a Gosse Nature Guide by Lisa J. Samuelson. Use of this text was permitted by the University of Alabama. Order your own copy of this great guide to Alabama’s trees here: https://www.amazon.com/Trees-Alabama-Gosse-Nature-Guides/dp/0817359419

Black Walnut Juglans nigra L.  

COMMON NAMES black walnut, American walnut  

QUICK GUIDE Leaves alternate, pinnately compound, with 8 to 24 leaflets; leaflets ovate, often lacking the terminal leaflet; fruit a round, ridged, corrugated nut encased in a yellow-green husk; bark dark brown and furrowed with interlacing ridges. 

DESCRIPTION Leaves are alternate, pinnately compound, deciduous, and up to 60 cm (23.6 in) long, with 8 to 24 leaflets and lightly pubescent rachis. Leaflets are ovate to ovate-lanceolate, 5-13 cm (2.0-5.1 cm) long, and nearly sessile; margin is serrate; underside is pubescent; autumn color is yellow. Mature trees often have an aborted or malformed terminal leaflet whereas young trees often possess a terminal leaflet. Twigs are stout, brown, and pubescent, with lenticels; pith is light brown and chambered; leaf scar is three-lobed with bundle scars in groups of three that form a monkey face. The terminal bud is conical to round and about 1 cm (0.4 in) long; scales are overlapping, brown-gray, and pubescent; lateral buds are superposed. Flowers are imperfect and appear after the leaves in the spring; staminate flowers are in drooping catkins; pistillate flowers are in terminal spikes. Fruit is a nut, round, up to 6 cm (2.4 in) wide, weakly ridged, and corrugated, with a sweet kernel; husk is yellow-green, indehiscent, and thick; fruit matures in the fall. Bark is brown to dark brown and furrowed, with interlacing ridges; inner bark is chocolate brown. The growth form is up to 30 m (100 ft) in height.  

HABITAT Moist, fertile soils.  

NOTES Black walnut is found growing with bitternut hickory, shagbark hickory, American beech, white ash, tulip-poplar, black cherry, white oak, northern red oak, basswood, and American elm. The wood has white sapwood and red-brown heartwood and is dense, fine-textured, strong, and hard. The wood is commercially valuable and is used for furniture, cabinetry, veneer, and rifles. The nuts are eaten by foxes, squirrels, and some birds. Beaver will occasionally use the bark.  

Juglans is Latin for “walnut tree,” nigra means “black,” referring to the bark or wood.