Show More


Black walnut


Classification:

Family:  Juglandaceae, walnut family
Genus, species:  Juglans nigra 

Leaves:
Leaves are pinnately compound, with a feathery appearance, more delicate-looking compared to ash leaves. Each leaf has 14 to 24 leaflets. Largest leaflets are located in the center of the leaf. Leaflets are lance-shaped, finely saw-toothed.

Bark:
Bark is dark brown, deeply furrowed.

Flowers:
Male and female flowers are separate but in same tree (monoecious), clustered in catkins.

Fruit:
Fruit is very hard, covered by thick green husk. Husk produces a dark-staining, strong-smelling juice. Green husk of fruit has been used to make a blackish dye since colonial times. Nuts are edible. Before eating or storage, nuts should be cured in a dry place for at least two weeks.

Twigs:
Interior of twig has a chambered pith.

Roots:
Black walnut produces juglone and releases it through its roots. Juglone is a chemical that is toxic (allelopathic) to some nearby competitor plants.

More Information:

The genus name Juglans is from the Latin for "walnut" and the species name nigra is from the Latin for "black."

Photos: