Maine Tree Species Fact Sheet

Common Name: American Elm (White Elm, Water Elm, Soft Elm or Florida Elm)

Botanical Name: Ulmus americana

 Tree Type: Deciduous

 Physical Description:

Growth Habit: American elm is a medium to fast growing large and graceful tree. It is found more often on rich bottomlands and moist soil along streams, but sometimes grows on higher ground.  The bark is dark gray with broad, deep, intersecting ridges, or often scaly.  The outer bark appears in cross sections and show layers of a whitish-buff color alternating with thicker dark layers.  The stems are slender, smooth, reddish brown in color and not mucilaginous when chewed.  The leaves are alternate, 3-6 inches long, with coarsely doubly toothed margins and uneven bases.  The upper surface is dark green and somewhat rough.

Height:  American elm grows to a height of 60-70 feet and has an average trunk diameter of 2–4 feet.

Shape:  American elm has a vase-shaped form in which the trunk divides into several erect limbs strongly arched above and terminating in numerous slender often pendulous branchlets; it also can have an “oak form” with more widely spreading, less arching branches; or have a narrow form with branchlets clothing the entire trunk.

Fruit/Seed Description/Dispersal Methods:

The flowers are perfect, greenish red, in fascicles of 3 or 4 and usually appear in the early spring.  They are not showy.  The fruit is greenish but may have a reddish tinge and is fringed with hairs.  It is a rounded, notched disc-shaped samara about a half inch long.  It matures in May–June.

Range within Maine:

American elm occurs throughout the state.  This species is hardy to Zone 3.

Distinguishing Features:

The trunk of the American elm often divides into numerous limbs, which form a vase-shape.  The twigs zigzag; the inner bark has alternate layers of brown and white and is not mucilaginous.  The leaves are slightly rough on the upper side.

 Interesting Features:

The wood is spiral and coarse-grained, hard, heavy, strong, tough and hard to split.  It is used for flooring, railroad ties, hoops, farm lumber and pulp.

Relationship to Wildlife:

Gray squirrels eat the flower buds, flowers and fruit.  Mice, squirrels, opossum ruffed grouse and northern bobwhite also eat the seeds.

Landscape Use:

At one time, this species was used extensively as a street and large lawn tree.  However, Dutch elm disease has now killed many of these trees.

Common Problems or Pests of the Tree in Maine:

Elms are subject to many pests and diseases.  Among them are Dutch elm disease, bacterial disease, cankers, leaf curl, leaf spot, powdery mildew, Verticillium wilt, aphids, Japanese beetles, borers, mites and scales.

References:

Forest Trees of Maine, Twelfth Edition.  Maine Forest Service/Department of Conservation. 1995.

Know Your Trees. Cope, J.A. and Fred E. Winch, Jr. Cornell Cooperative Extension. 1992.

 Manual of Woody Landscape Plants, 5^th Edition.  Dirr, Michael A.  Publishing L.L.C. 1998.

United States Dept. of Agriculture: Silvics of North America

http://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/ulmus/americana.htm

The Illustrated Encyclopedia of Trees. More, David and John White. Timber Press. 2002.

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