White oak leaves and marble-sized galls. Galls are growths on plants caused by invasions of parasites, viruses, fungi and bacteria -- making galls centers of activity for both attacks on a plant's ...

Galls are abnormal growths on a part of the plant. They can be caused by bacteria, insects, mites and fungi. They can be on any part of a plant and are the overgrowth of plant tissue in response ...