Extension Forestry

Black Walnut - Juglans nigra

Leaves are alternate compound with more than 11 leaflets.

The black walnut is one of our best known and most valuabletrees.  It is a large, straight-stemmed timber tree with an open crown.  When grown in the open it is a short-trunked, low-branching,wide-spreading tree.  Widely planted for its nuts, lumber and forornamental purposes, it is found over the eastern United States asfar west as Nebraska, Kansas and Texas.  It is found quite generallyover Iowa, scattered among other timber.  Growing chiefly alongbottomlands, in coves and on lower slopes, it prefers a deep, rich,moist but well-drained soil.

The tree has large, pinnately compound leaves, 12 to 24 inches long with 15 to 23 leaflets.  The leaf stems are covered with fine hairs,but are smoother than butternut.  The leaflets are 2-1/2 to 3 inches long, yellowish green in color, tapering at the endand toothed along themargin.

The twigs are brownish, stout, blunt and with prominent leaf scars.  The pith is cream colored and chambered, dividing into thin plates or segments

The fruit is a large, rounded, brownish black nut with a hard, thick, finely ridged shell enclosing a rich, oily kernel.  The kernel is edible and highly nutritious.  The nut is enclosed in a solid, non-splitting husk, and is borne on the tree singly or in pairs.

The thick bark is dark brown in color and divided by deep fissures into rounded ridges. It has a chocolate brown under-color when broken from the tree.

Last Update: January 22, 1998