THE ASHES
White Ash, Green Ash, Black Ash
Oleaceae - The Olive Family

World-wide, the olive family has between 22 and 30 genera with over 400 species.  Most are not trees.  Lilacs, forsythias, privet, and jasmine are also members of the Oleaceae, as are olives.  Most grow in the northern hemisphere.  The ashes are all oppositely-branched and have compound leaves.  They all have fruits called "samaras", which are like one-winged helicopters from the maple family.  Twigs are stout and relatively few, giving the crown a "dead look" when the leaves are off.  The ashes look similar to each other.  Distinguishing characteristics are leaflet stalks, lateral buds, branching form, general appearance, and habitat. Most of the ash in Michigan has been killed by the emerald ash borer.  

  WHITE ASH  (Fraxinus americana)
  Other Names:   Biltmore Ash
  Key ID Features:  Leaves, Opposite Branching, Twigs, Bark

White ash LEAVES are 8-12 inches long with 5-9 STALKED leaflets. The leaf margins have broad, shallow teeth.  BRANCHING is opposite.  Twigs are stout.  The first set of side BUDS are close to the chubby, brown terminal bud. The top of the leaf scar forms a deep "U" or smile.  FRUITS are about 1-2 inches long and a quarter-inch wide.  BARK is light gray on young trees and thick, narrow-ridged,and firm on older trees.  The trunks grow tall and well-formed, making ash a rather satisfying find in the woods.  HEIGHTS will reach 70-80 feet with 2-3 foot diameters.  White ash is a MINOR PART of northern hardwoods and other upland hardwood forest types. Common pests: fall webworm, gypsy moth, cankerworms, emerald ash borer, ash dieback.

  GREEN ASH  (Fraxinus pennsylvanica)
  Other Names:   Red Ash, White Ash, Swamp Ash, or Water Ash
  Key ID Features:  Leaves, Opposite Branching, Twigs, Bark

Green ash LEAVES are very similar to white ash. The leaves are 6-9 inches long with 7-9 leaflets. Compared to white ash, green ash leaves are usually shorter and with one less pair of leaflets. The first set of LATERAL BUDS are tight against the terminal bud, and the top of the leaf scar is straight across. The tips of the branches tend to be much more "flattened" than other ashes.  BRANCHING is opposite and somewhat droopy. TWIGS are less stout thatwhite or black ash. The GENERAL APPEARANCE of green ash is much scruffier than white ash. Heights reach only 50-60 feet with diameter rarely over two feet. The BARK has distinct horizontal cracks and the ridges tend to be somewhat platelike. The bark is not as firm as white ash. Green ash typically grows near water courses, along shorelines,and along roads.  It's usually fairly open grown.  Common pests: fall webworm, gypsy moth, cankerworms, emerald ash borer, ash dieback, beavers.

  BLACK ASH (Fraxinus nigra)
  Other Names:   Basket Ash, Brown Ash, Hoop Ash, Swamp Ash, or Water Ash
  Key ID Features:  Leaves, Opposite Branching, Twigs, Bark, Habitat

Black ash LEAVES have 7-11 leaflets without stalks.  Leaves are 8-12 long.  The first set of side BUDS are usually at least a 1/4 inch from the terminal bud but not always.  The top of the leaf scar is slightly notched.  TWIGS are the stoutest among the ashes.  BRANCHING is opposite and upright.  Black ash usually occurs in rich swamps on the floodplains of slow-moving streams. It does not usually get far from these wetland area. It grows 60-80 feet in height with diameters of 1-2 feet.  Common pests: fall webworm, gypsy moth, cankerworms, emerald ash borer, ash dieback, beavers.

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This site created and maintained by Bill Cook, MSU Extension Forester for the Upper Peninsula of Michigan.   Editing and modification is ongoing.  Submit suggestions, questions, and corrections to cookwi@msu.edu or call 906-786-1575.