Fraxinus pennsylvanica Marsh.

author: Jenny Janis

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Higher Taxon:

The following is according to Cronquist's system.
Mabberley, D.J., 1987

common names:

(Collingwood et al., 1974)

Photo of samara fruit of the Fraxinus pennsylvanica species.
It is very similar in shape as the Fraxinus americana species.
photo courtesy of the University of Georgia Herbarium

Identification: In 1785, Marshall distinguished F. pennsylvanica as distinct from F. americana. He discussed it in his book Arbustrum Americanum. His specimens were collected in the United States, but the exact location was not found. The current location of the original specimens also was not found.Stafleu et al., 1981
Depending on the physical environment, the Green Ash grows to variable forms and sizes. The range of height is from medium to large with the maximum height reaching around 100 feet.Brown et al., 1990 In a mature tree, the diameter ranges from 1 to 2 feet. The maximum diameter is 3 feet. The tree top is rounded "with slender, spreading branches [and] it has ashy gray branchlets marked by pale lenticels."Collingwood et al., 1974 The leaves can reach 10-12 inches long with 7-9 lanceolate, 4-6 inch leaflets. Their margins are entire or finely toothed. On top of the leaf, the color is dark green and the underneath is pale green. The petiolule is 1/8-1/2 inch long.Preston, R., 1976 The flower is described as "dioecious, appearing late in spring as the leaves begin to unfold, in a rather compact tomentose panicle, covered in the bud with ovate rusty-tomentose scales; staminate flower with a minute obscurely toothed cup-shaped calyx, and 2 stamens, with short slender filaments and linear-oblong light green anthers tinged with purple; calyx of the pistillate flower cup-shaped, deeply divided, as long as the ovary gradually narrowed into an elongated style divided at apex into 2 green stigmatic lobes."Sargent, C.S., 1965 The fruit form is samara. It's length ranges from 1-2 1/2 long. The seed cavity is slender and the wing is terminal or reaches to about midway up the seed cavity. The fruit matures in the late summer and early autumn.Preston, R., 1976 The twigs are described as "moderately stout, often flattened at the node, grayish green, glabrous; terminal buds with 4, pubescent, rusty brown scales; leaf scars half-round, usually straight across at the top rather than notched."Brown et al., 1990 Green Ash bark is said to resemble young Black Walnut trees. There are "narrow fissures separated by interlacing ridges."Brown et al., 1990
There are drawings of the leaves on the Genus Fraxinus page.

Geography: The range of the Green Ash extends from Nova Scotia to eastern Alberta. From eastern Alberta, the range runs a diagonal line south through the middle of Montana, eastern Wyoming and down to eastern Texas. Then it flows east along the Gulf of Mexico reaching into Northern Florida's Atlantic coast.Collingwood et al., 1974

Table I: North American Distribution of F. pennsylvanica

Fraxinus pennsylvanica

North America:
Continental United States; Canada
Yes Neill, R., 1978
Eastern North America:
United States east of Mississippi;
Ontario and eastern Canada
Yes Neill, R., 1978
Southeastern United States:
Yes Neill, R., 1978
Southern Appalachian States:
Yes Neill, R., 1978
Coastal Plain rare Jones et al. 1988
Piedmont Widespread Neill, R., 1978
Blue Ridge Mountains Widespread Neill, R., 1978
Great Smoky Mountains National Park Yes Neill, R., 1978
Ridge and Valley Yes Neill, R., 1978
Cumberland Plateau Yes Neill, R., 1978
Central Arch yes Neill, R., 1978
Georgia Widespread Neill, R., 1978
Clarke County, Georgia common Jones et al. 1988
Sams Farm Common Jenny Janis, Pers. Ob.
Old Field no Jenny Janis, Pers. Ob.
Wetland yes Jenny Janis, Pers. Ob.
Woods yes Jenny Janis, Pers. Ob.
1-Hectare Plot no Jenny Janis, Pers. Ob.

Natural History: The Green Ash lives in a variety of climates. From the cold winters of southern Canada to the mild ones of northern Florida, the Green Ash maintains itself. The staminate and pistillate flowers bloom in tight clusters on different trees. The fruit ripens in the fall, but can remain on the tree into the winter.Collingwood et al., 1974 Green Ash stands avoid interspecific competition by growing in nearly pure groups or stands. Privet has been noted as a competitor. Sycamore, Sweetgum and Cottonwood also can compete with Green Ash on land next to wet flats.

How to encounter: This species is most often found along streams. This is especially true in the Georgia Piedmont. Neill states that Green Ash stands usually have more females than males.Neill, R., 1978 Commonly, it is along overflow river bottoms which are not covered by water for most of the growing season. This is why another name for F. pennsylvanica is Swamp Ash. In the Mid-West prairies, Green Ash is found mostly along rivers and streams. The Mississippi River basin has been noted to have the most abundance of Green Ash.Collingwood et al., 1974 There are specimens of the Green Ash in the University of Georgia Herbarium. One can go to Sam's farm located off Georgia highway 78, north of Athens, just past mile marker 16, and find this species near and in the wetlands.


  1. Brown, C. & Kirkman, K. 1990. Trees of Georgia and Adjacent States. Timber Press, Inc. Portland, Oregon.

  2. Collingwood, G.H. & Brush, W. 1974. Knowing Your Trees. The American Forestry Association. Washington, D.C..

  3. Jones, Samuel & Coile, Nancy. 1988. Distribution of the Vascular Flora of Georgia. Deptartment of Botany. University of Georgia. Athens, GA.

  4. Neill, Richard. 1978. Reproductive Morphology of Green Ash (Fraxinus Pennsylvanica Var. Subintegerrima. A Dissertation Submitted to the Graduate Faculty of the University of Georgia in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy. Athens, GA.

  5. Mabberley, D.J., 1987. The Plant Book: A portable dictionary of the higher plants. Cambridge University Press. New York, N.Y.

  6. Preston, R. 1976. North American Trees. The Iowa State University Press. U.S.A.

  7. Sargent, C.S. 1965. Manual of the Trees of North America. Dover publications. New York, N.Y.

  8. Stafleu, Frans & Cowan, Richard. 1981. Taxonomic Literature. v3. International Association for Plant Taxonomy. Boston, MA.