Identifying Green Ash

Below are a set of links to pages and pdf documents that help in identifying green ash (fraxinus pennsylvanica).

NDSU handbook
Wikipedia entry
Virginia Tech Factsheet
CalPhotos
Fall color - gonative.org

Other common or similar species (Virgina Tech factsheets)
Sugar maple (Acer saccharum)
Red oak (Quercus rubra)
Silver maple (Acer sacharinum)
Basswood (Tilia americana)
Ohio buckeye (Aesculus glabra)
Burr oak (Quercus
Box elder (Acer negundo)
Walnuts (Juglans species, here black walnut, but also butternut)
Bitternut Hickory
Kentucky Coffeetree (Glymnocladus dioicus)

Note that you might be most likely to confuse green ash with box elder, walnut, bitternut hickory, Kentucky coffeetree, and perhaps Ohio buckeye.

Green ash has smooth leaflet margins, to a point, while box elder leaflet ends are "toothed".

Green ash and the various walnuts both have compound leaves. This means that leaflets come from a main leaf "stem", called a rachis. In most walnuts, the rachis is much longer than in green ash, and there are 10 to 24 leaflets from the rachis. In green ash, there are typically 7 to 9 leaflets. Also, note the bark and fruit are different (see photos in factsheets, above).

Bitternut hickory is perhaps the most similar to green ash at first look, as it has similar leaves, somewhat similar bark and size, and the leaves also turn yellow in the fall. Bitternut hickory has large, round nuts, while green ash has smaller clusters of winged seeds, and bitternut hickory also has large, furry, sulpher-yellow buds, while green ash does not. Finally, bitternut hickory leaflets are finely serrate, meaning they have little "teeth," or "sawtooth" patterns on the leaf edges, while green ash leaflets do not.

Kentucky coffee tree has bipinnate leaflets, meaning there is a rachis, the then smaller rachii coming from the rachis, with leaflets. In addition, seeds in Kentucky coffeetree are in large pods, the bark is different, with a "flakier" appearence, the tree is smaller, the stem and braches rarely straight (green ash stem and branches are almost always straight) and the leaflets smaller, and fatter at the base.

Ohio buckeye leaves differ in that the compound leaf is "plamate," meaning there is no or an extremely short rachis, and the leaflets all come from the same, central point.