White Ash (Fraxinus americana)
[ Trees > Hardwoods > Ashes . . . ]
Forest Types: Oak-Hickory, Beech-Maple, So. Riverine, Appalachian Cove
by Michael Kuo
Habitat: Varied; surviving well in several different forest types; fond of moist soil, but able to survive elsewhere; growing east of the Great Plains.
Stature: 50-80 feet high; to 3 feet in diameter; with an open crown.
Leaves: Compound; composed of 5-9 leaflets arranged more or less in pairs, with a single leaflet at the end; leaflets dark green above and whitish to greenish below, candle-flame-shaped; edges slightly toothed or nearly smooth; stemlets to 1/2 inch long.
Bark: Dark grayish; deeply cut into X shapes (or "diamond" shapes, depending on your perspective).
Fruit: A small samara or "wing" 1-2 inches long; hanging in dense clusters; the hard, seed part not extending far into the flat, wing part (see below).
White ash is nearly identical to green ash, and a suite of subtle characters must be used to separate the two trees. In theory the leaves of white ash have a more whitish underside, but this character is unreliable in my experience. The stature of the two trees is usually (but not always) distinctive; the branches of green ash tend to spread outward somewhat more. The samaras of the two trees are usually different: the hard, seed part extends more into the flat, wing part in green ash than in white ash:
. . . but the leaf scars on twigs seem to me to be the most reliable character for comparison. The white ash leaf scar is generally larger, more puckered looking, and more U-shaped:
When samaras, twigs, leaves, and stature are considered together it is usually possible to make an identification--but the features do seem to intergrade between the species sometimes, making precise identification difficult. Some authors emphasize the extent of the serrations on the leaflets, but I find this character unreliable.
Frequently Associated Mushrooms:
Cite this page as:
Kuo, M. (2010, November). White ash (Fraxinus americana). Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/trees/fraxinus_americana.html