What Kind of Tree Is a Slippery Elm?

Keys to Identification

• The term mucilaginous applies to the sticky, moist inner bark of slippery elm. The Native Americans and early pioneers chewed this bark when thirsty and the bark had important medicinal qualities, according to the Missouri Botanical Garden. The tree possesses a vase-like shape, with a broad crown of branches. The new twigs are downy and the winter buds are red. The reddish-green flowers of March and April yield a papery, rounded samara. The leaves are elliptical, feature asymmetrical bases, have serrations on their edges and noticeable veins running from the midrib out to both sides.

Geography and Growing Conditions

• The range of the slippery elm includes from central New England west to the Great Lakes, south through the eastern Great Plains into Texas and east to northern Georgia and South Carolina. The range falls within that of the American elm. Slippery elm grows from U.S. Department of Agriculture plant hardiness zones 3 through 9. It prefers a damp, fertile soil in which to grow, but has the ability to develop in dry areas.

Slippery Elm Vs. American Elm

• Slippery elm ("Ulmus rubra") in many ways is just like its close cousin, the American elm ("Ulmus Americana"). The most notable differences, according to the Ohio Department of Natural Resources, are that slippery elm has fewer main branches, the limbs are higher on the trunk, the leaves have a rough texture and the tree grows better in dry soils. The leaves of slippery elm are a bit longer, being between 4 and 7 inches in length as opposed to the 3- to 6-inch long leaves of American elm.

Problems

• Like American elm, the slippery elm falls victim to Dutch elm disease, but not to the incredible extent that its cousin does. This ailment, spread by flying bark beetles, concentrates its attack on the tissue within the tree able to bring water to various parts of the plant. Once this occurs, the slippery elm wilts, loses leaves and eventually may die. A viral disease known as phloem necrosis also affects slippery elm, with similar symptoms such as defoliation. Caterpillars, mealy bugs and various beetles are common insect pests of the tree.