Butternut, Juglans cinerea, is a relatively uncommon hardwood tree native to the forests of eastern North America. Butternut is a close relative black walnut, Juglans nigra. Both species have compound leaves, produce large edible nuts, and grow on relatively mesic sites. Butternut is shade-intolerant and requires full sun to regenerate successfully. For more information on the species, see Silvics of North America.

Butternut’s plant profile is also described at the USDA NRCS website.

Butternut is valued for its soft, easily-turned wood, nut meat, and other uses. The number of butternut trees on the landscape has been declining over the last few decades from a likely introduced pathogen, Ophiognomonia clavigignenti-juglandacearum (Oc-j). The pathogen may have been introduced from Asia but its origin, and site of the first introduction remain unknown. Sadly, no natural resistance to this pathogen has been found in butternut.

Butternut hybridizes naturally with Japanese walnut, Juglans ailantifolia, which was planted in the US by private landowners in urban plantings. These hybrids may resemble either parent or have characteristics of both. This article describes the traits of both J ailantifolia and J cinerea. If you find attributes of J ailantifolia on a particular tree, then the tree is likely a hybrid of butternut and Japanese walnut. If a tree has no traits of Japanese walnut, then it could still have hybrid genotype: a laboratory test, of the DNA, is required to confirm pure J cinerea lineage.

Our objectives with this page are to create a landing page with information for conserving the species. See the tab “Strategies for genetic improvement” for suggestions for a breeding plan.