Growth - Looks like a cherry to me!
In my densely overgrown rose area, every year I get volunteer white oaks (right below canopy of a white oak). In cutting them out, I noticed many had growths (ground level/ base of tree) that looked just like bunches of Ranier cherries. What are they? Seem to be saprophytic, not harming the oaks at all. Just curious, don't appear to be harmful
We think this looks like a type of gall. Galls are an abnormal swelling of plant tissue, often a response to insects or mites. There is more information about galls here on our website. There are many different forms. https://extension.umd.edu/hgic/topics/shade-tree-galls If you are curious, you could cut one open and see if there are any signs of a tiny larva inside.