This valley oak, in the Chinese Camp area, is showing signs of a possible canker rot infection. The bark is bursting in numerous locations on the main bole. Overall, the tree looks healthy, with new leaf growth, and fullness in foliage. The tree has extensive sapsucker holes. A small swimming pool was constructed nearby.
Dr. Swiecki states “In canker rots, the decay column extends out to the cambium in some places, causing a localized canker that can callus over, especially if the tree is otherwise vigorous. ”
Collected by Steve Deaver, 12 September 2016, in Twain Harte, Tuolumne County, growing out of a crack in a shaded area of driveway.
Images below include cross sections.
Thanks to Matthew J. L. Kilger of https://www.facebook.com/groups/MushroomIdentification/ for the identification.
Click to enlarge.