Elm tree identification involves looking for distinct characteristics in the tree's leaves, stalks, seeds, shoots and bark. These parts vary based on the type of elm and look different in a healthy tree versus a diseased tree.
Elm trees have oval-shaped leaves with saw-tooth edges. Leaves range from 1 to 6 inches in length. Winter shoots are dark grey or purple with slightly darker purple or brown buds. Elm trees have coarse and rough bark that forms a pattern of intersecting diagonals.
An elm may also be identified by its height. Some elms, such as the Scotch elm, reach heights of 132 feet. Others, such as the camperdown elm, reach 10 to15 feet. The shape of the elm is a helpful identifier. The canopy of the tree is rounded, cylindrical, umbrella-shaped, oblong or vase-shaped.
Diseased elms show specific characteristics in their leaves and shoots. The leaves may be retained and appear yellow or discolored. Both leaves and shoots are often wilted. When an elm is inflicted with disease, symptoms of decay develop rapidly.
Elms originated in Central Asia during the Miocene period 40 million years ago. They have since spread to Europe and North America. Eight species of elm are endemic to North America.