Black Walnut (also known as Eastern Black Walnut)
Kingdom: Plantae, Division: Tracheophyta, Class: Magnoliopsida, Order: Fagales, Family: Juglandaceae, Genus: Juglans, Species: J. nigra · Juglandaceae (Walnut family) · Pinnately compound deciduous leaves
Species
Juglans nigra
Leaf Type
Pinnately compound deciduous leaves
Family
Juglandaceae (Walnut family)
Shape
Lanceolate to ovate-lanceolate leaflets with tapered tips
Size
Individual leaflets are approximately 3-4 inches long and 1-2 inches wide, making up a total leaf length ranging from 12-24 inches for the entire compound leaf.
Margin
Serrate (finely toothed)
Arrangement
Alternate arrangement along the twig
Rarity
Common throughout its native range, frequently encountered in both wild and cultivated settings.
Color & Pattern
Bright to medium green on the upper surface, slightly paler and more yellowish-green on the lower surface. No prominent variegation, typical healthy summer green coloration.
Venation Pattern
Pinnate venation with a prominent, pale central midrib and clearly visible secondary veins branching outwards.
Texture & Surface
Smooth to slightly pubescent underneath, particularly along the veins, with a slightly papery yet firm texture.
Description
The black walnut is a large, majestic deciduous tree known for its dark, furrowed bark, large compound leaves, and delicious, hard-shelled nuts enclosed in a green husk that turns black upon maturity.
Key Features
Pinnately compound leaves usually lacking a terminal leaflet, finely toothed leaflet margins, distinctive chocolate-brown chambered pith inside twigs, and round green fruits.
Habitat
Thrives in deep, rich, moist, and well-draining soils found in mixed deciduous forests, along streams, and in open fields and valleys.
Geographic Range
Native to eastern North America, stretching from southern Ontario through the central and eastern United States down to Texas and Georgia.
Condition Notes
The foliage appears generally healthy with good color and normal vigor, displaying only minor insect feeding marks typical for mature summer foliage. Health grade: Good.
Interesting Facts
Black walnut trees produce a chemical compound called juglone, which inhibits the growth of many other plants beneath or near its canopy, a phenomenon known as allelopathy.
Medicinal & Uses
The wood is highly prized for fine furniture, gunstocks, and cabinetry due to its rich dark color and durability. The nuts are edible and widely used in baking. Hulls are used to produce natural brown dyes.
Ecological Role
Provides critical food and habitat for numerous wildlife species, including squirrels and birds that consume the nuts. Acts as an important canopy tree in eastern hardwood forests.
Similar Species
Other walnut species such as the Butternut (Juglans cinerea), which has sticky, hairy leaves and a terminal leaflet, and various species of hickory (Carya), which generally have fewer leaflets and different bud structures.
Foraging Tips
Look for large compound leaves with 15-23 leaflets, absence of a terminal leaflet, and crushed leaves emitting a distinctive, spicy, citrus-like aromatic scent.
Toxicity Warning
Non-toxic for humans to consume the nuts, but the chemical juglone found in roots, hulls, and leaves can be toxic to horses (causing laminitis) and inhibits certain plants like tomatoes and apples.