Andricus stellulus

Distinctive star-headed gall. Never protruding to the opposite surface, mature galls are typically associated with a brown necrosis around the point of attachment which extends laterally to the leaf-blade margin.

Pedicellate, monothalamous, occurring singly (infrequently clumped) on either dorsal or ventral surface. Exterior of stalk rugose, delicately reticulate to glabrous on disc; green with occasional red and yellow markings when fresh, brown or black at maturity. Disc: four to six points around perimeter, supported by slender stalk, reticulate with fine striations radiating from central darkened spot on upper surface; varies from ovoid to cupped in profile; centrally supported on stalk. Attached to leaf-blade vein by slightly enlarged basal ring. Galls usually stand upright on leaf surface.

Host:
Quercus dumosa

- John A. Burnett: (1974) A New Cynipid Wasp From California (Hymenoptera)^©

Reference: https://www.biodiversitylibrary.org/page/53913490#page/313/mode/1up