Calling all arborists. Need help identifying tree feature.

June 10, 2012 6:00 AM

What could have caused this unusual feature in the bark of a mature post oak tree? Another view.

This is a 150+ year old post oak that is being studied for its potential to be an Indian trail marker tree. I am asking here about the specific bark feature. Our local arborist does not think it was caused by a cut branch. He thinks these features occur when something is embedded in the bark. Thank you!

posted by punkfloyd to science & nature (2 answers total)

Probably some sort of insect gall. It's amazing how big the gall can get sometimes.
posted by HuronBob at 6:11 AM on June 10, 2012 [1 favorite]

Galls can also be caused by bacteria or fungi.

I'm not an arborist, but it seems like normally when bark grows around a wound, such as putting a nail in the tree, you see a visible callus that is smooth and rounded around the edge.
posted by abirdinthehand at 8:49 AM on June 10, 2012