Dark, discolored wood exposed by cutting a dying limb of coast live oak with oak branch canker, or bot canker, Diplodia corticola.

A close-up view of dark, discolored wood exposed by cutting off a dying limb of coast live oak, Quercus agrifolia, with oak branch canker, or bot canker, Diplodia corticola.; San Diego County, California Credit: Akif Eskalen
Credit: Akif Eskalen