Please help my identify this tree?

Question

its leaves look EXACTLY like those on a fern plant. its has an undivided dark bark. it's all over chicago. I looked in books and even tried arbor day foundation's web site. any ideas what tree it could be?

i see it in the park and lining the streets.

Answer 1

Try googling Ginkgo Biloba.  I think that may be what you're seeing.

Answer 2

some kind of locust, try looking at those varieties