Shade Tolerance = Intermediate
Soil Moisture Niche = Moist Sites
Vertical Preference = Dispersed Canopy
Both green and white ash have opposite compound leaves. Hickories, black walnut, mountain ash and black locust also have compound leaves, but their leaves are alternately arranged. In fact, the ashes are the only trees in the Park with both compound and opposite leaves except yellow buckeye which displays distinctive palmately compound leaves with leaflets radiating from a central point.
Mature ash bark breaks into rectangular gray plates, but the plates are spongy. You can easily dent them with a fingernail. In winter, look for the oppositeness of the twigs; then stick a fingernail into the bark.
Distinguishing the ashes from each other is not so easy. Pull a leaf off and look at the leaf scar where the leaf attaches. Green ash leaf scars have axillary buds that stick up above the leaf scar. White ash buds are almost entirely encircled by the leaf scar. An axillary bud is the small bud found where the leaf stem attaches to the twig. Fortunately for dendro-nerds, green ash is rare in the Park, growing only occasionally along low elevation streams. White ash is the ash of the Smokies.
White ash produces winged seeds relished by wildlife. The strong resilient wood is prized for tool handles and furniture. White ash shares family connections with the olive tree, the producer of edible olives without which the lowly pimento would have no proper mission in life!