With all the concern with vein pocket gall, people will often become concerned with anything on a leaf that does not look natural. However, many pin oak trees have a fuzz that is found between the mid-vein and side-veins on the bottom side of a pin oak leaf. This fuzz is natural and is not a cause for concern.
Note that there are fuzzy galls that can infect a pin oak leaf but they are not limited to the “V” between the mid-vein and side-vein. Though these galls also do not cause significant harm, they are not natural to the leaf but are caused by an insect or mite. (Ward Upham)
