Rock elm and hackberry are rare. Elm fruits are round samaras which ripen in the spring. Hackberry has berry-like fruits that ripen in the fall. The twigs of elms and hackberries have a zig-zag arrangement. Terminal BUDS are angled from the TWIG at about 45 degrees.
American elm has one of the most easily recognized tree silhouettes .
Once a major component of our hardwood forests and a common urban tree, almost all trees larger than 8 inches in diameter have been killed. Samaras are bit larger than American elm but without the distinct notch and fuzzy margin. Slippery elm is almost always found along streams and on floodplains . It is commonly found with red maple, silver maple, and black ash. Like the American elm, slippery elm is also susceptible to the Dutch elm disease.