Walnut, American (Juglans nigra) American Black Walnut, Black Walnut While walnut grows throughout the United States and southern Canada, its commercial range is confined largely to some fifteen Central States. This one species produces a greater variety of figure types than any other, approached only by mahogany. Its coloring ranges from dark purplish brown to a light gray-brown with patterns that can be plain or highly figured. It is an exceptionally stable wood used in gunstocks, cabinetry, furniture and architectural woodwork. Moderate to high cost dependant upon figure and cut.