Black Ash, Fraxinus nigra Marsh
DISTINGUISHING CHARACTERISTICS: Leaves once-pinnately compound, opposite, 12 to 16 inches long; leaflets 7 to 13 in number (usually 9 to 11), oblong lanceolate, 3 to 6 inches long, not stalked, conspicuously toothed, glabrous except for tufts of orange-brown hairs where they join at the leaf stem. Winter twigs moderate to stout, gray, glabrous; leaf scars half-round to nearly-round; bundle scars numerous and close together, forming a fine curved line. Buds similar to green ash but usually black. Flowers very small, polygamous or dioecious, apetalous, appearing with or before the leaves in spring; staminate in short, compact panicles, pistillate in open panicles. Fruit a paddle-shaped samara 1 to 1 1/2 inches long, often persisting in winter; wing notched at apex, surrounding the flat, indistinct seed cavity. Bark gray, scaly, becoming shallowly and rather indistinctly furrowed on large trees.
SIMILAR TREES: Green and white ash have stalked leaflets, brown buds, and samaras with distinct seed cavities that are rounded in cross section.
IOWA DISTRIBUTION: Native as far west as the Des Moines River Valley. Not commonly planted.
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