Skip to main content
You are here
Facebook icon
Pinterest icon
Twitter icon

Juglans nigra (black walnut)

A North American tree with dark-coloured timber and bark, black walnut produces timber and edible nuts (seeds) used in confectionery.
Juglans nigra at Kew Gardens

Juglans nigra at Kew Gardens

Species information

Scientific name: 

Juglans nigra L.

Common name: 

black walnut, American walnut

Conservation status: 

Not assessed according to IUCN Red List criteria.

Habitat: 

Mixed woodland.

Key Uses: 

Timber, edible seeds, ornamental.

Known hazards: 

See below.

Taxonomy

Subclass: 
Superorder: 
Rosanae
Order: 
Fagales
Family: 
Juglandaceae
Genus: Juglans

About this species

Black walnut gets its name from both its dark timber and dark brown to black bark. All walnut trees (Juglans species) produce edible seeds (known commonly as nuts), but those of black walnut are notoriously difficult to extract from their husks; it is the common walnut, Juglans regia, that is cultivated commercially for its nuts.

The leaves, bark and fruits of black walnut contain juglone, a red crystalline compound, which is known to be active against tobacco mosaic virus (a virus that causes an infectious disease in crops such as tobacco and tomatoes). When rubbed, the leaves of black walnut give off a strong aroma that most people find pleasant.

Medicinal Uses

Black walnut was used medicinally by Native Americans to treat skin conditions, psychological illness and miscellaneous diseases.

Synonym: 

Wallia nigra (L.) Alef.

Genus: 
Juglans

main info

Help us solve a 2,000 year-old mystery

Aloe vera in Kew's Princess of Wales Conservatory

Find out how you can help Kew scientists unlock the benefits of Aloe vera.

State of the World’s Plants report – out now

Pantanal in Brazil

Kew has launched a ground-breaking new report highlighting the global status of plants.