There are 6 different elms found growing in Central Texas:
1. American Elm - larger tapered point leaves/ samara split
2. Slippery Elm - similar to American Elm with large tapered point leaves but rougher, prominent split veining on abaxial surface/samara rounded.
3. Winged Elm - slender elongated pointed leaves/early blooming/corky / samara prominent hooks at end split. more common to eastern half of tx.
4. Cedar Elm - small, stiff blunt leaves/ late blooming/corky on young trees/samara small split.
5. Chinese Elm - small neatly serrated leaves not as stiff as cedar elm and teeth are more rounded/ samara small split/red splotched bark
6. Siberian Elm - leaves smaller than American elm, no taper/samara rounded. more common to west and northwest of central tx.
Two of these are non-native species, Ulmus parvifloria (Chinese Elm) and U. pumila (Siberian Elm)
Siberian Elm is most typically found in the panhandle, and more arid regions of Texas. Chinese Elm is frequently found in urban areas and planted as a landscape tree. It successfully reproduces and spreads to surrounding areas. Chinese Elm and Cedar Elm (U. crassifolia) are fall blooming species and can hybridize.
Winged Elm (U. alata), American Elm (U. Americana) Slippery Elm (U. rubra) and Siberian Elm are early bloomers.
Occasionally it can be difficult to distinguish between Chinese elm and Cedar elm, usually in young seedlings before the tree has bark and when leaves are immature.
Winged elm and Cedar Elm can also look somewhat similar, but the leaves of U. alata are more pointed. And of course, it blooms early and U. crassifolia blooms late.
American elm and Slippery elm can also be difficult to distinguish between, with the samaras the easiest way to identify. Slippery elm is rarer to find growing.