Black ash (Fraxinus nigra)

Black ash photograph; © MN DNR

Form

Medium-sized tree with a height of 35' to 75', a diameter of 12" to 24"; crown is rounded and made up of a few short branches; trunk is supposed to be straight, columnar, but is often leaning or crooked.

Bark

Grayish on older portions of tree, furrowed and somewhat separated into thin scales that are easily rubbed off; new growth of light green color.

Leaf

Opposite on stem, length 9" to 16", pinnately compound with seven to 11 yellowish green leaflets each 4" to 5-1/2" long, oblong in shape, and not stalked except the terminal leaflet; terminal bud is large and pointed; leaves smooth on both surfaces; turn yellow to brown in autumn.

Fruit (seed)

Flat, winged, one-seeded samara, 1" to 1-1/2" long; the wide, thin wing that is rounded or slightly notched at the end nearly surrounds the seed part; seeds usually germinate and start growth in the second year.

Range

Fairly plentiful in the state except in the western half; most abundant in cold, moist locations and along low banks of streams; shade intolerant, slow growing.