Agree! The tree with our state's name, and it is a great heritage tree here.
There are apparently different spellings offered, and I'm not a user of ICBN to determine who is right.
I learned this plant as Gymnocladus dioicus (versus the spelling in the database link Lin offered). In fact, several other database entries use the spelling I know.
Online search shows mostly G. dioicus, though the Missouri Botanical Garden shows G. dioica.