Hi all. I was hoping someone could help me id this tree. I haven't had any luck googling it. The closest I come up with is something tropical. Here where I live it's common for it to drop below zero in the winter.

Of course I didn't take a picture of the tree. But I picked some seedpods up and planted some of the seeds and a couple came up within 5 or 6 days. It grows really fast.

I think I left the one you see here in a peatpot too long.

Anyway, the seedpods are 6 to 8 inches and the seeds are about the size of edible beans, though flatter. The birds love them. They killed 5 or 6 sprouts right after they came up. They dug them up out of the pots and left the plants laying there. I think it was a Stellar's Jay who could smell them, once they sprouted.

The only thing I can tell you about the tree is that its bark is smooth and light-gray and the leaves are a lot smaller than the leaves of a locust tree. And it doesn't have thorns.

Any thoughts?

Can you describe the flowers?

I suspect you have a "mimosa tree":
Mimosa Tree (Albizia julibrissin)

If you find smooth, brown, rectangular seeds inside the seed pod, that would be more evidence toward A. julibrissin.

I saw them all the way up into northern West Virginia a couple weeks ago, Z5/6 area.

Gleditsia triacanthos var. inermis

All the seedlings of my Honey Locust look like your seedling. When young the Trunk is smooth but when older it will produce horrendous thorns. Beautiful tree but the thorns on all branches and trunk are demons . I cut all thorns back at Human level quite a feat and painful! But Beautiful foliage treein the Autumn. Grows great here in Northern MI