The preferred habitat of pumpkin ash is inundated river bottoms and swamps where it develops a swollen base, thus the reference to a pumpkin. It is scattered about the state in small pockets but most prevalent in the southwestern counties. The leaves have five to nine leaflets with the rachis, or central stem of the leaf, densely pubescent. Its twigs are stout and grayish brown in color. The emerald ash borer has been found in Indiana. This insect, accidentally introduced from Asia, is lethal to all native ash species, and the potential for destruction of native ash trees rivals that of Dutch elm disease on American elm.