Elm trees (scientific name Ulmaceae) are hardy deciduous trees. The elm genus includes between 20 and 40 different species. Elms are among the most popular shade trees because they can withstand poor growing conditions, including air pollution and irregular watering.
First, look at the tree's leaves. The leaves of elm trees are green and flat, and the tree drops its leaves in winter. This type of tree is a deciduous broadleaf.
Examine the leaves to see how they grow onto the tree. Elm leaves grow onto woody stalks, which in turn grow onto the larger branches of the tree. Such leaves are called compound leaves.
Check to see whether the stems of the compound leaves grow onto the stems of other compound leaves, or whether only one compound leaf stem grows out of the tree. Elm tree leaves follow the latter arrangement.
Look at the individual leaves. On an elm tree, there is a space between where one leaf attaches to the stalk and where the next leaf attaches on the opposite side of the stem. These are called alternate leaves.
Carefully inspect one leaf. An elm leaf is oval, longer than it is wide, and has small indentations along its edges. Its base is not square nor exactly symmetrical.
Now, look to see whether buds are emerging from the stem. Elm tree buds are visible all along the stems.
If it's late spring or early summer, see if you can find any fruits growing on the tree. Elm trees bear small, round fruit. Each has a single seed inside.
Look at the bark of the tree. Most elm trees have uneven, rough, gray-brown bark that has creases and ridges. As it ages, the tree's bark tends to get grayer.