Re: Oak "berries" ???
Larry Barrett
It sounds like oak gall.
I asked Mr Google and this is one of the hits from WalterReeves.com where a reader wrote in with a similar question:
Q: Have you ever seen this? My oak tree has been producing little red berries or acorns! I know what an acorn looks like and these are not acorns. But they were growing from the tree in several locations on the tree.
I do have wild cherry trees growing in my backyard also. Could this be some kind of cross breed of oak and cherry?
A: Oaks seem to have more gall-making insects afflicting them than any other tree. There’s bullet gall, jumping gall, gouty gall, sower gall and hedgehog gall. There’s oak marble gall, horned oak gall, noxious oak gall and oak apple.
All galls are caused by an insect of some sort wounding some part of a plant in order to lay eggs. The insect injects hormones at the wound which cause the tissue around that spot to grow abnormally. The abnormal growth often serves as home for the insect’s eggs and young.
Since the insect depends on the continued growth of the plant in order to have a place to lay eggs in the future, galls rarely harm the host.
