Galled, curled leaves of coast live oak infected with oak leaf blister fungus, Taphrina caerulescens.

Galled, curled leaves with yellowish bulges on upper surface of coast live oak, Quercus agrifolia, from oak leaf blister, Taphrina caerulescens (Hemiascomycetes). Berkeley, Alameda Co. by JKC.  Credit: Jack Kelly Clark
Credit: Jack Kelly Clark