Environment Planet Earth Identify the Elms Trees in the Elm Family - Ulmaceae By Steve Nix Steve Nix Writer University of Georgia Steve Nix is a member of the Society of American Foresters and a former forest resources analyst for the state of Alabama. Learn about our editorial process Updated February 19, 2020 DEA / RANDOM/De Agostini Picture Library/Getty Images Environment Weather Outdoors Conservation Elms are deciduous and semi-deciduous trees comprising the genus Ulmus, family Ulmaceae. Elms first appeared in the Miocene period about 40 million years ago. Originating in central Asia, the tree flourished and established itself over most of the Northern Hemisphere, including North America. Eight elm species are endemic to North America, and a smaller number to Europe; the greatest diversity is found in China. The Common North American Elm Species American elm rock elm slippery elm Leaves: alternate, asymmetrical, uneven at base, toothed.Fruit: a drupe or winged key. ash | beech | basswood | birch | black cherry | black walnut/butternut | cottonwood | elm | hackberry | hickory | holly | locust | magnolia | maple | oak | poplar | red alder | royal paulownia | sassafras | sweetgum | sycamore | tupelo | willow | yellow-poplar ID Glossary