I picked these seed pods from a tree growing in a parking lot in Loveland, Colorado. I'm hoping they're distinctive enough that someone recognizes them and can ID the genera or species from the seeds and seed pods. Thank you!

I believe this is the Kentucky Coffeetree, Gymnocladus dioicus

Here's our database entry with photos of Kentucky Coffeetree (Gymnocladus dioicus)

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.

Yes, the garden.org database uses the Catalogue of Life as a source for information, which shows G. dioica as the accepted scientific name and G. dioicus as the synonym but it is the same tree and a beautiful one at that; I sure wish it grew this far south!

Many thanks to everyone! Perhaps I'll try germinating them when the season slows down a bit.

These seeds need to be scarified and soaked before they will germinate. There are various methods described online but the simplest way would be to rub the seed on a file to remove a part of the very hard seed coating. After the filing process let the seeds soak in water overnight. Then plant like any other seed.

Thanks Kelly!