Another gall from Sam in SC

I found this on the edge of a patch of woods that borders a large pond in the lyman area. It was found around an oak tree branch. The branch is approximately 1cm in diameter and the white ball of interest is approximately 6cm in diameter. When I opened it up I noticed there were a bunch of what appeared to be stem like growths between the exterior surface ofthe white ball and the surface of the branch.


Hi Sam,

this has been submitted previously because it is so unusual.  It is actually an oak gall, specifically a wool-sower gall.    Woolly sower galls are caused by parasitic gall wasps belonging to the genus Callirhytis.  The irritation of the wasp larvae cause this growth, which is not a normal part of the tree.



Dr. Steven R. Hill, Botanist  SCNPS


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