6. BLACK WALNUT, Juglans nigra

Early spring image of Black Walnut tree, Juglans nigra.

The Black Walnut is a tall, graceful tree with a slender form.  In Spring, it takes on a distinctive green hue that is a blend of emerging foliage and both male/female flowers.


Flowers of the monoecious Black Walnut tree.

Juglans nigra is a monoecious tree - male and female flowers appear on the same tree.  Top left are the male pollinators, called catkins.  They are easy to see.  The female flowers are smaller, harder to see, and start out green before turning the red shown above.


The summer view of the Black Walnut tree. During Summer, the Black Walnut is a showy tree with its large, compound leaves and slender canopy. The bark is tightly furrowed and gets darker with age - one of the reasons it is called "Black" Walnut.


The compound leaf of Juglans nigra, and its baseball sized-fruit.

Black Walnut trees have large, compound leaves composed of 23 leaflets. The leaflets are arranged in opposite fashion.  The fruit grows during the summer, reaching the size of a tennis ball in good years. You will find the fruit singly, in pairs, and small clusters.


Fall view of Black Walnut at the Westmoor Arboretum.

The large leaves turn a golden color in fall. In some years, the tree remains quite full during this season, and in other years it tends to drop its leaves early. Notice the dark bark.


Two phases of the fruit of Black Walnut Tree.

A common scene as the leaves change - the large fruits of the Black Walnut.  The fruit is green when it falls, but quickly ripens to this dark color (another reason it is called Black Walnut). Technically, this fruit is called a drupe, and the actual nut is inside the drupe.


The Black Walnut showcases its dark bark, soaring branches, and slender canopy during the winter months.