Q. macrocarpa
galls on a white oak. not 100% sure on this ID, but this seems to be the best match visually. pics 1 and 2 are of the abaxial surface of the leaf, pics 3 and 4 are of the upper surface
On Quercus macrocarpa
Host tree Bur Oak
on a bur oak
I think? These are white oak leaves
What a wonderful afternoon spent with friends at Thora Hart Park -- we focused on galls today (thanks Adam and Kim!). So many different galls... and so many that I can't remember the names of. :-/ Will update ID's later on! :)