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White Ash


Family: Oleaceae, olive family
Genus species: Fraxinus americana

Leaves are pinnately compound. Each leaf has 7 or more leaflets. All leaflets within one leaf are usually about the same size.

Bark is furrowed with diamond-shaped grooves. Bark is gray or yellowish in color.

Flowers are very small, produced in small clusters. Flowers emerge before leaves in the spring. Male and female flowers are on separate trees (dioecious).

Fruit is 1 to 2 inches long. Fruit is flat, looks like the blade of a canoe paddle. Seed is almost entirely surrounded by the fruit. Fruit hangs in clusters, matures in late summer, wind-dispersed.

More Information:

The genus name Fraxinus is from the Latin for "ash." 

Emerald Ash Borer:  Ash trees are being affected by the Emerald Ash Borer, a non-native invasive species of beetle.  Adult beetles are a bright metallic green and about ½ inch long.  The adults feed on ash leaves but do not damage the trees.  Males hover around trees, locate females, and drop onto the female to mate.  The female deposits eggs between bark crevices or in cracks.  The eggs hatch about two weeks later.  After hatching, the larvae chew through the inner bark of the tree and feed on the tree’s vascular tissue.  The larvae gradually mature into adults, and the adults exit the tree by chewing holes feed on the inner bark of the trees.  The feeding activity of the larvae kills the ash trees by disrupting the tree’s ability to transport water and nutrients.  The emerald ash borer has killed tens of millions of ash trees in North America during the past 10 to 15 years.