The winged fruits of Black Ash have a conspicuous notch at the base. So do fruits of the angular-twigged Blue Ash of the Central States. The latter, however, are shorter and wider than Black Ash fruits. The wood of Black Ash is heavy, brown, and tough.
Black Ash is a northern tree, common in swamps and in moist soils. Its dark green leaves look black in the forest shade. The bark is dark gray, with shallow, interlocking cracks. The twigs are smooth, gray, with light lenticels and dark buds. The 7 to 11 leaflets are finely toothed, hairy along the large veins, and without a stalk.
