TRADE NAME: American Elm
GENERAL DISTRIBUTION: Native to eastern North America, naturally occurring from Nova Scotia west to Saskatchewan (Canada) and Montana, and south to Florida and Texas. Common along the Gulf Coast.
WOOD VALUE: Is coarse-grained, heavy, and strong. It lacks durability, warps and splits badly during seasoning. Is used in the manufacture of boxes, baskets, crates, barrels, furniture, agricultural implements, fuel wood and caskets. Elm veneer is used for furniture and decorative panels.
OTHER USES: Before the advent of Dutch elm disease, American elm was prized as a street ornamental in many cities in North America.
SEASONAL DEVELOPMENT: The time of flowering, seed ripening and seed fall varies by about 100 days between the Gulf Coast and Canada. The flower buds swell early in February in the South. The trees are in flower two to three weeks before the leaves unfold. The fruit ripens as the leaves unfold or soon afterward. The seed is dispersed as it ripens and seed fall is usually complete by the middle of March in the South and by the middle of June in the North.
- A deciduous, fast-growing, long-lived tree which may reach 175 to 200 years old, with some as old as 300 years.
- In dense forest stands, may reach 100 to 200 feet in height and 48 to 60 inches in diameter at breast height. Heights of 80 feet are common on medium sites, but on very wet or very dry soils the species is often 40 to 60 feet tall at maturity.
- The alternate, double-toothed leaves are 2 to 5 inches long and 1 to 3 inches wide.
- The dark gray bark is deeply furrowed.
- The perfect flowers are borne in dense clusters of three or four fascicles. The fruit is a samara consisting of a compressed nutlet surrounded by a membranous wing.
- The root system varies according to soil moisture and texture. In heavy, wet soils the root system is wide-spreading, with most of the roots within 3 to 4 feet of the surface. On drier soils, it develops a deep taproot.
- Has suffered greatly since the introduction of Dutch elm disease from Europe around 1930. Since then, the disease has spread over much of the U.S.
- The disease is caused by the fungus Ceratocystis ulmi. Spores of this fungus are carried by American and European bark beetles from diseased trees to healthy trees.
- The beetles breed only in dead, dying, or recently cut elm wood and winter as larvae under the bark. In the spring, adults emerge and fly a short distance (usually less than 500 feet) to feed in the twig crotches or small branches in the upper parts of the living trees. As the beetles feed, the spores are introduced into the tree and the tree becomes diseased. After the spores have been introduced into the tree’s vascular system, the xylem becomes plugged and a toxin is produced.
- The trees wilt on the small branches and eventually on the whole limbs.
Sources: USDA Plant Index; U.S. Forest Service (FS. Fed.US); Tree Services