@daemonicusprince That might be hypoxylon, a weak opportunistic fungus that develops on the wood of well-shaded trees. Their presence within the wood of the tree manifests in the form of cankers (areas of dead wood that slowly grow over time like a scab). These cankers vary in colour from a yellowish brown to grey to black.

If this is an oak, then it’s likely Hypoxylon atropunctatum. My guess at the regular pattern is the fact that fungal infections in a tree follow the tree’s circulatory system up and down the trunk, resulting in localized flareups along paths of least resistance.

#hypoxylon #fungi #trees #canker