Ordered a Northern Catalpa a couple months ago and it finally started to sprout some leaves about two weeks ago. Much to my surprise the leaves look nothing like a catalpa. These are more of an elliptical shape with serrated margins. The tree was was delivered leafless with a bare roots and did have a label wrapped around it indicating it was a catalpa. I've emailed the company about this but have gotten no response. I realize the leaves are still young and so may be hard to definitively ID, but thought I'd give it a shot. Any ideas what it could be?

You're right, that's not a Northern Catalpa. But, if the only leaves sprouting on this tree are at the base, you have a bigger problem (the top of the tree is dead). I hope you sent photos to this company. And, I hope you read the reviews before you ordered.

A new "branch" has started to sprout farther up on the tree, so luckily it is alive higher up. I got it from Arbor Day. I got a catalpa from them that I planted at my old house and had no issues (it actually grew fairly quickly and was a good 10' tall when I moved). Wanted one for my new house.so figured I couldn't go wrong ordering from them again. So much for that theory...

I ordered a River Birch from Arbor Day once and got a Lilac.

It appears to have opposite, compound leaves which narrows it down quickly (assuming it is a native species). I believe it is one of the Ash trees (Fraxinus sp.). Another possibility would be Box Elder (Acer negundo) but the serrated leaf margins point more toward ash.

I was leaning toward Box Elder. It will be easier to tell when the leaves mature some.

Young box elders' trunks are usually green.

I agree - NOT Catalpa sp., especially with apparently pinnate compound leaves.

DeClercq can be more generous with images - including the WHOLE plant - and then the additional leaves that are growing and bud scars along the stem, and any buds evident where the leaf attaches to the stem. Clearly show whether the arrangement of leaves emerging along the trunk are opposite or alternate. This will narrow the field of potential ID candidates.

These are all good ID features beyond these few emergent partial leaves currently formed.