It is probably a hybrid elm. Leaves definitely look like American and bark looks more like a Chinese. Don't the nursery people know? I wouldn't want to do my shopping at a garden center that couldn't identify their trees.
Ideal for providing shade in backyard and along neighborhood streets, the elm tree is one of the most common trees. Its many varieties are present all over the world. There are more than 30 species of elm, but most share several common...
It is always tricky getting the identity of an elm. But more or less they are all treated the same for bonsai. The techniques are the same across the genus, so if it takes you a couple years to nail down for certain which species or hybrid elm you have that is not really a problem.
The botanically significant traits are flower color, and the phenology of WHEN they flower, some flower spring, some species late winter, some flower in autumn. Of course only an older tree would flower so this is not something you will see any time soon, though mature bonsai elms will flower even in a bonsai pot. Next trait, and this can be used during winter, is the arrangement of scales on the winter buds. The protective scales, or sheath leaves that cover the winter buds, the pattern is diagnostic for species. The arrangement of the scars of the vascular bundles in the abscission scar where the leaves were is another diagnostic trait used to separate one elm from another. For example, the vascular bundles can be in a 'U' shape or 'V' shape or other patterns. Leaf shape & size and number of veins is also diagnostic. Often to be certain, you check each trait as the year goes by, and by the end of a year or two you will have the checklist. THen you sit down with a botanical dichotomous key, and check the questions off, jump to the next until you have your identity. Pain in the ass.
Or you can sit and read Wikipedia and go through each entry. Some have great detail as to what identifies the species, some of Wikipedias entries are pretty vague. All in all I've found most of Wikipedia's information accurate, even though sometimes it is woefully vague sometimes. It rare that I say, "that's plain wrong". Most of the time Wikipedia is correct to really good.
I've spent about the last year trying to figure out what kind of elm tree I have. Some kind of hybrid. Here's what I've learned.
American elms and Chinese elms do NOT readily hybridize with anything. In recorded history, American elms have been crossed with something else less than five times. Maybe only twice. It has to do with chromosomal compatibility.
On the other hand, Siberian elms and Slippery elms cross ALL THE TIME in the wild. So I think that's what you have. This leaf in particular looks suspiciously like a small, single-serrate, slippery elm leaf with a symmetrical base. I.e. a hodge-podge of traits from those two species.
The OP, @JesusFreak is in southern Georgia, so the number of possible species is quite large. There are at least 3 or 4 native elms, and probably a dozen possible introduced, invasive elms. While I agree that a Siberian elm, Ulmus pumila, is a distinct possibility, there are other that are possible. To sort it out with certainty, you really need to use a botanical key. You must do things like count the number of veins on each side of the midline of the leaf. And you must do this count for several leaves to be sure you got the "average" and not just one deformed leaf. You must examine leaves for where there are hairs and where the leaf is smooth. You write these things down. A picture of the seed from the tree in question is also helpful. Then you work your way through the keys. Anything less than using a key is just guessing. Elms are a confusing group, you can not separate one elm from another without putting some work into it. Just "eyeballing" is just guess work, and highly likely prone to error.
I'm happy calling it an elm. All elms are pretty much treated the same as bonsai. But if you want to "know" you need to go to the keys. If you do not "go to the keys" I would say it won't qualify for the "Native tree, Native Pot Challenge", as chances are good it is a Chinese elm, or a Siberian elm or a hybrid of one of these with a native elm.