I found these intriguing looking galls on the underside of a red oak in Rockcliffe Park. Oaks are particularly interesting for the number of different types of galls they have, most made by Cynipid wasps, as was this. I thought the galls were especially interesting, for they look like little pots. Charley Eiseman maintains a great blog, Bug Tracks, where I found more information about similar galls: http://bugtracks.wordpress.com/ This is not a good photo, but I post it only because the gall is rather interesting. Next summer I'll try for a better shot.