Walnut Tree Identification: Black Walnut Leaves and Nuts

A black walnut is a tall tree with long feather-like compound leaves, dark diamond-ridged bark and round green fruit about the size of a golf ball. These four checks settle it:

• Count leaflets. The Missouri Department of Conservation (MDC) gives leaves 1 to 2 feet long with 11 to 23 leaflets, each 3 to 5 inches long. Tree Identifier notes the end leaflet is often missing or smaller than the rest, which makes many leaves look even-numbered.
• Cut a twig lengthwise. MDC and the University of Minnesota both give the chambered pith as a distinct feature: the soft center of the twig is divided into small light-brown compartments, like a ladder.
• Look at the bark. The University of Minnesota describes it as dark gray-black with sharp ridges forming a diamond pattern. MDC adds that it shows chocolate brown when scraped.
• Smell a leaf or husk. The National Park Service notes both have a spicy citrus smell when crushed or scraped.

In winter, the NPS points to the leaf scar: heart-shaped with three dots.

Several trees share the long compound leaf. How to separate them:

• Butternut (Juglans cinerea): Tree Identifier gives 11 to 17 leaflets, light gray to tan bark and a dark chocolate-brown chambered pith. MDC describes the fruit as rather cylindrical, with a nut that has 4 lengthwise ribs; Wikipedia calls it oval-oblong, while black walnut fruit is round.
• English (Persian) walnut (Juglans regia): Wikipedia gives only 5 to 9 leaflets, most often 7. This is the walnut sold in grocery stores. MDC notes it is cultivated but does not naturalize in Missouri.
• Hickories: Tree Identifier notes hickory twigs have a solid pith, not chambered.
• Tree of heaven: leaflets have smooth edges with few teeth, and crushed leaves smell foul, like rancid peanut butter (Tree Identifier). See our tree of heaven identification page.

The pith check is the quickest: cut a twig lengthwise. Chambered and light brown means black walnut; chambered and dark brown means butternut; solid means hickory or another tree.

MDC describes the fruit as a green, rounded husk 1.5 to 2.5 inches across covering a round, hard, dark brown or black nut, ripening September to October. The NPS notes the green balls are held from midsummer well into fall. Tree Identifier describes the shell inside as deeply ridged and rock-hard.

The University of Minnesota and MDC both describe the seed as edible, and MDC notes Missouri is the world's top producer of black walnuts. The nuts are not eaten straight off the tree: Wikipedia describes removing the husk and drying the nuts first, and notes the hard shell needs special cracking tools. The husk stains skin and clothing, so wear gloves.

As with anything gathered wild, confirm the tree's identity before eating, and throw out nuts that look moldy or smell off. If someone reacts after eating, contact a doctor or Poison Control at 1-800-222-1222.

Black walnut releases a chemical that harms many plants nearby. Wikipedia explains that the roots, inner bark, husks and leaves contain hydrojuglone, which turns into active juglone on exposure to air or soil. The University of Minnesota names tomatoes and apples as especially sensitive, and Wikipedia adds pines and birch.

Tree Identifier gives a root zone of 50 to 80 feet from the trunk and lists tomatoes, peppers, azaleas, blueberries, potatoes and asparagus as sensitive, with beans, corn, carrots, hostas and ferns as tolerant. A wilting vegetable bed near a large tree with compound leaves is a common way people discover they have a black walnut.

There is no fixed price by age. University of Missouri Extension explains that timber buyers pay by volume and quality: diameter, log length, and defects such as knots, seams and decay. Its example: a 10-foot log 12 inches across yields 40 board feet, but at 20 inches it yields 160 board feet, and if it meets veneer grade the price per board foot may be 2 to 10 times higher, up to 40 times the value in total.

MU Extension notes that walnut demand is cyclic and recommends selling in periods of high demand, leaving the harvest to experienced buyers and professional loggers, and hiring a professional forester, whom it says helps landowners receive more money. MDC calls black walnut Missouri's most valuable tree. Because knots, seams and decay lower the price, a short or defective yard tree is usually worth far less than its size suggests.

On how rare it is: Wikipedia lists black walnut as Least Concern and describes it as common and increasing in eastern US forests. But the National Park Service notes that because of the wood's value, the number of large individuals remaining in the landscape is extremely low.

Research and drafting for this page used AI assistance. Every measurement, date and claim was then checked against the sources listed below, which were opened and read on 2026-09-25. Where two sources give different numbers, both are shown.