Possible fungus on Oak tree

Asked October 4, 2016, 5:57 PM EDT

I would like to know what these balls on a White Oak (I think) tree are. In particular, I'd like to know if they are toxic or poisonous--I just could find nothing like it in a couple of tree identification books. Thank you. Elaine Covard

Montgomery County Maryland

1 Response

This is a twig gall,commonly found on white oak. It is caused by an insect, a wasp, that causes this abnormal growth to develop.Mites can also cause galls but appear on the leaf surface. They are not toxic http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG31%20Insect%20and%...