Foreshortened stem covered with leaf clusters... Asphondylia foliata Gagne
Beneath the leaf clusters the gall is clublike, 2-4 mm long, and monothalamous. The smooth galls are at the tips of axillary buds of foreshortened stems and are seen only in spring. Host: A. polycarpa. Distr.: California. Ref.: Hawkins et al. (1986).
”- Raymond J. Gagne: (1989) The plant-feeding gall midges of North America©