@jeffdc I know you're the expert here. Can you walk me through step by step? So we're looking at some sort of petiole gall. The leaves suggest a white oak, right? And I should be going to https://www.gallformers.org/ armed with the host, the location on the plant, etc?
Fernowii (Q. alba X Q. stellata)? Or just a weird Q. stellata? Straight alba and stellata were nearby. Branchlets pubescent and some scattered stellate hairs abaxially on leaf.
Northern pin oak in fall season