These are unique galls that develop on the underside of leaves. They are small, rounded, solitary, or clustered, and they are scattered haphazardly over the leaf blade and along the leaf margin. Their positions are marked on the upper surface by small, white spots, each with a tiny escape hole. The presence of white spots against the green background of the upper leaf blade makes the galls striking and easily recognizable. The galls are of the same whiteness as the underside of the leaf blade. Frequently the plant is heavily galled. These interesting and beautiful galls are caused by Eriophyes ceanothi.

Eriophyes ceanothi occurs on redroot, an evergreen shrub found from British Columbia to Colorado and California. Specimens of mites were first collected in Oregon and subsequently in California.

- Hartford Keifer,Edward Baker,Tokuwo Kono,Mercedes Delfinado,William Styer: (1982) An Illustrated Guide to Plant Abnormalities Caused by Eriophyid Mites in North America^©