A medium tree with dark wood and edible nuts. Among the most valuable hardwoods in North America.

Also called: Eastern Black Walnut

Native status: Native to eastern US

§ Quick facts

SizeMature height 22–46 m (75–150 ft); trunk diameter 1.2–2.4 m
WeightN/A
Lifespan150–250 years
OrderFagales
FamilyJuglandaceae

§ Encyclopedia

Juglans nigra, the eastern American black walnut, is a species of deciduous tree in the walnut family, Juglandaceae, native to central and eastern North America, growing mostly in riparian zones.

Source: Wikipedia — Juglans nigra Licensed under CC BY-SA 4.0

§ Identification

Field marks. Tall straight tree with deeply furrowed dark gray-brown bark; pinnately compound leaves with 11–23 toothed leaflets; large round green husks containing dark-brown shell with rich oily kernel.

Similar species. Butternut (J. cinerea — smaller, oval rather than round nuts; declining from canker disease). Hickories (5–9 leaflets, different husks). English Walnut (introduced; thinner husk, easier to crack).

Voice. N/A

§ Diet & behavior

Diet. N/A — photosynthesis

Behavior. Most economically valuable native US hardwood — single large logs can sell for tens of thousands of dollars for veneer use. All parts (roots, leaves, hulls, nuts) produce juglone, an allelopathic chemical that inhibits growth of many other plants within the "drip line" of the tree. Native peoples used the green hulls as fish poison (juglone temporarily stuns fish). Nuts highly nutritious but very difficult to crack; squirrels are the primary natural seed dispersers.

§ Range

Eastern North America

§ Habitat

Open woodlands, fields

§ Threats

Logging for valuable timber.

§ Conservation status

According to the IUCN Red List, the black walnut is currently classified as Least Concern.

§ What helps

Support sustainable forestry.

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§ Further reading

§ Sources cited

  • USDA Plants Database
  • Walnut Council
  • USDA Forest Service Silvics Manual
  • IUCN Red List 2017