mushroom growth on bark of old big leaf maple
Our very old big leaf maple sits on the west property line near a doug fir. The soil drains quickly, is full of rocks, and uphill from the Columbia slough near 42nd and Fremont. The tree was pruned three years ago and again this week by a tree Service. The two arborists declared the tree healthy. This fall a new growth of mushrooms was noted roughly 8 ft up on the bark. I have also observed small black mushroom growth at the base of the tree in spring of previous years. I would appreciate any thoughts you can share regarding this development. Thank you. Steve
This mushrooms looks like Pholiota squarrosoides, which is a decomposer and not implicated as a parasite, though it can decompose wood on a tree. It is common on hardwoods such as cottonwood and maples. I can't comment on mushroom growth on the base of the tree unless I can see a good photo.