|Shape and Distribution
Pumpkin ash is a large tree, reaching heights of up to 130 feet, with a trunk diameter of up to 5 feet on sites with excellent growing conditions. The tree grows best in areas where there is standing water at the surface well into the growing season. In these areas, the tree often develops a swollen or pumpkin-shaped base. The crown is broadly rounded, with thick branches.
Pumpkin ash grows in the wet soils of bottomlands and swamps and is present in the southernmost counties and along the Wabash River in southern Illinois. It occurs frequently with bald cypress and tupelo.
The name pumpkin ash is derived from the enlarged base or "butt" that the tree develops when growing on sites that remain wet for most of the growing season. This enlargement can be pumpkin shaped, and is probably like buttresses and cypress knees - it provides extra stability for the tree, which is rooted in peaty, wet, and generally unstable soil. Pumpkin ash is sensitive to drought and fire. It is the only ash in Illinois to have velvety-hairy twigs and usually toothless leaves.
The bark of pumpkin ash is similar to that of green ash. It is gray to brownish gray, has tight furrows and distinct ridges and becomes scaly with age.
The twigs are also similar to green ash. They are stout, brownish gray and more densely hairy than those of green ash.
The buds are conical, brown, and hairy.
The leaves are opposite, compound and 8-16 inches long. There are 7 - 9 leaflets, each up to 10 inches long and up to half as wide. Leaflets are lance-shaped to elliptic with pointed tips and tapering toward the base. They are finely toothed or more usually smooth along the edges. The upper surface is green to yellow green and smooth and the underside is paler and densely hairy.
Pumpkin ash is dioecious, which means that is has male (staminate) or female (pistillate) flowers and that either male or female flowers are borne on separate trees. The flowers appear in clusters in April before leaf out, and are inconspicuous, without petals, and greenish-purplish.
The fruits are winged, but not flattened. They are 2 - 3 inches long and 1 1/2 inches broad, oblong, and usually rounded at the tip. The wing almost completely encloses a single seed at the base. Wood duck, songbirds, and rodents eat the seeds. White-tailed deer browse the twigs and leaves.
Pumpkin ash has heavy, strong, hard wood. Tool handles and farming implements are made from pumpkin ash. Pumpkin ash is also used for manufacture of boxes, paper pulp, and fuel.