Bark canker

Symptoms - The bark canker fungus commonly attacks older, injured trees. On entering a wound, the fungus grows into the inner bark and cambium. A canker begins as a sunken oval shape with blackened inner bark. Its development is rapid and the infected tree often cannot form a defensive callus tissue. Cankers can expand 1 m a year, reaching a final length of 3 to 4 m, before the outer bark sloughs off to expose the sooty, black, inner bark. After tree the tree dies, tiny (1 to 3 mm) grey, cup-shaped fruiting bodies are produced in blackened areas of raw patches. The dead bark resembles soot as it crumbles in the hand.