Black walnut is native throughout the state.

Grow 50-75 feet (may reach maximum height of 125 to 150 feet)

The leaves are alternately arranged on the twig, compound with 1 to 23 leaflets, and ranging in size from 1 to 2 feet. The terminal leaflet is either absent or much smaller than the leaflets near the middle of the leaf. The leaflets are 2 1/2 to 4 inches long, finely toothed and slightly hairy below the surface.

Although black walnut has been used a lot as a shade tree, it is considered to be a poor choice because its relatively open crown provides less shade than other species, its leaves tend to drop early and the nuts tend to be messy. However it is prized for its nuts which proved a distinctive taste for baked products. The Iowa Nut Growers Association continue and have made several selections of black walnut for the outstanding size and quality of their nuts.

Iowa continues to rank as one of the leading producers of walnut lumber and veneer. The rich brown color, attractive grain of the wood, and the woodworking quality of the wood makes it the most valuable timber tree in Iowa.