T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Juglans nigra (Black Walnut)

Kingdom:   Plantae
(Unranked):        Angiosperms
(Unranked):        Eudicots
(Unranked):        Rosids
Order:     Fagales
Family:   Juglandaceae
Genus:   Juglans
Species:     J. nigra
Binomial name: Juglans nigra
Common name: Black Walnut, Eastern Black Walnut

The black walnut is a large deciduous tree with sturdy trunk with large branches and a large spreading crown and is a native of the Midwest and east-central United States. This large tree can attain heights of 30–40 metres. The bark is grey-black and deeply furrowed. It has leaves up to 60 centimetres, with 11 to 23 leaflets, oval with pointed tips and the end one often missing. Light green in spring, butter yellow in autumn. The male flowers are in drooping catkins petalless and 50-120 mm long. The female flowers are solitary or in small clusters of two to five and are 20-50 mm long. These ripening during the autumn into a nut with a brownish-green semi fleshy husk with a brown corrugated nut.
Juglans nigra is known for its high-quality wood which is hard, heavy and strong. Stable, straight grained and easily worked and varies from light to dark brown depending on age. The sapwood is nearly white. It is used for furniture, paneling, cabinet work and interior finishing and rifle stocks. Oil is pressed from the seeds. In New Zealand it is grown on farms, parks and gardens and parks.

A young Black walanut tree

Black Walnut (Juglans nigra) detail of nut and leaves

The underside of the leaves.


Trunk of the above tree