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Ash Tree Identification

Tagged as: leaves, ash trees, Ash leaves

Every tree species has a unique combination of defining characteristics. Variations in leaf size, shape, and arrangement can assist in identification. Use the following images comparing ash to other trees in determining if your tree is an ash.

Ash leaves are arranged oppositely meaning leaves and branches are located across from each other. The leaves of many other species are arranged alternately.

Blue ash branching Beech branching

Opposite branching and leaf arrangement of blue ash (Fraxinus quadrangulata)

Alternate branching of beech (Fagus sp.)

Ash leaves are compound and made up of more than one distinct leaflet. In contrast, simple leaves such as those on most maples are undivided.

Green ash leaf Red maple leaf

A compound leaf of green ash(Fraxinus pennslyvanica)

A simple leaf of red maple (Acer rubrum)

Most ash leaves have 5-9 leaflets with a single terminal leaflet. If there are less than 5 leaflets or more than 9, it is generally not an ash. However, occasionally black ash and blue ash can have up to 11 leaflets.

Black ash leaf Black walnut leaf

5-9 leaflets on black ash (Fraxinus nigra) leaf with a single terminal leaflet

12 leaflets on black walnut (Juglans nigra) leaf

 

The largest ash leaflets occur near the middle of the leaf. By comparison, the largest hickory leaflets are near the tip of the leaf.

Large black ash leaflets Hickory leaflets

Largest leaflets near middle of black ash (Fraxinus nigra)

Top three leaflets of hickory (Carya ovata) are largest


Ash leaves are pinnately compound. Leaflets are arranged along either side of a central axis like a feather. This differentiates ash from palmately compound leaves such as those on buckeyes where leaves originate from a single point.

White ash leaf Buckeye leaf

Pinnately compound leaf of white ash (Fraxinus americana)

Palmately compound leaf of buckeye (Aesculus sp.)

The margins of the ash leaflets are toothed and not lobed as seen on the box elder.

Blue ash leaves Box elder leaves

Toothed leaves of blue ash (Fraxinus quadrangulata)

Lobed leaves of box elder (Acer negundo)

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