Was inside my water bottle (that had had a lid open)
On Pale Smartweed (187321750).
Not sure what this is. Nothing on gallformers.org, no credible matches from iNat, ditto an image search.
Gall? Fungus? Both?
Whatever it is, it was in several places on this one plant, but I didn't see it on nearby plants.
Help appreciated.
On a oak leaf.