They look like hops, but they are from ironwood, a common understory tree. Ironwood (Ostrya virginiana) is also known as hophornbeam because its fruits look like hops. Ironwood is generally considered a weed tree, but it provides some winter food for wildlife because its seeds persist on the tree well into winter. I saw them on the ground and in the trees on January 14th. Each bladder like structure contains a single seed. I tasted a couple of the seeds, and they didn’t taste like much to me. Watch for them the next time you are in the woods.