Live Oak Gall

If I found this gall on an English Oak I would say it was made by Cynips quercusfolii a small black Gall Wasp. If you google Gall Wasp you will maybe find your species. The subject of Plant Galls is very fascinating.Every species of tree and plant have galls,some species galling only only one species.I'm sure if you research you will find the subject has been well covered in North America,as in England. I believe North America has aruond 800 species of Gall Wasp. If you look at wildflowers and trees as a hobby then look at each one more carefully to find galls and micro fungi,but be careful it can become quite an obsession.I will post a few Oak Galls.

These are insect galls. The tree or plant species would be helpful.