Strange markings on a red maple tree’s bark. What caused it?
Answer
Red maple target canker. Northern Woodlands discussed this disease back in 2011 in an article on bark, noting that, “In this region, the perennial target canker – a series of concentric cracks in the outer bark – is found exclusively on red maple, though not on every tree. The circular cracks mark the cycles of the disease’s progress and the tree’s subsequent compartmentalization. Neither the tree nor the fungus seems to gain the upper hand, and this competition can continue year after year.”
This week’s contest winner was Rob Anderegg