How to identify walnut and butternut

Black walnut (*Juglans nigra*) and butternut (*Juglans cinerea*) are the two native walnuts of eastern North America. Both are valuable trees -- for timber, nuts, and wildlife -- but they are under serious threats. Butternut is in decline across most of its range due to butternut canker disease..

Black walnut (Juglans nigra) and butternut (Juglans cinerea) are the two native walnuts of eastern North America. Both are valuable trees — for timber, nuts, and wildlife — but they are under serious threats. Butternut is in decline across most of its range due to butternut canker disease. Understanding what separates these two species, and how to identify each with confidence, matters for landowners and naturalists.

Genus-level identification

Chambered pith: Per Penn State Extension, cut any twig lengthwise with a pocketknife. The center of the twig is divided into small, dark, chamber-like sections separated by thin cross walls. Hickory, ash, and most other hardwoods have solid, continuous pith. The chambered pith is definitive for Juglans.

Large compound leaves: Walnut leaves are alternate, pinnately compound, and large — 12–24 inches in total length with 11–23 individual leaflets. The terminal leaflet is often smaller than the adjacent lateral leaflets or absent — which is the opposite of hickory's pattern. Per NC State Extension, the large leaf size, strong spicy-nutty fragrance when crushed, and terminal leaflet reduction together separate walnut from hickory at a glance.

Leaf scar shape: The leaf scar left when a leaf drops is prominent. In both walnut species, the upper margin of the scar has a notched or pad-like cluster of lenticels that resembles a "monkey face." Per UMass Amherst Extension, this distinctive leaf scar shape is often cited as a winter identification tool.