Clusters of hairless, slightly bumpy globular galls attached to the lower midrib or occasionally major side veins of Quercus macrocarpa in late summer. Clusters typically contain 3-6 individual galls, each of which is white with a scar or nipple at its apex, often turning black but less consistently so than in Andricus robustus. Older galls may turn pink or orange. The galls are very similar to those formed by Andricus robustus on Quercus stellata but apparently differ in their host, their more nearly spherical shape with less pronounced necks, their white rather than green color early in growth, and their typically greater size and smaller numbers per cluster.