Inonotus glomeratus(Polyporus glomeratus)

From Bugwoodwiki

USDA Forest Service. 1979. A guide to common insects and diseases of forest trees in the northeastern United States. Northeast. Area State Priv. For., For. Insect and Disease Management., Broomall, PA. p. 123, illus.

Inonotus glomeratus (formerly Polyporus glomeratus) is an important decay organism of sugar maple, red maple, and beech. A black, cinder-like mass of fungal material forms in the openings created by a dead branch stub. This material is sterile, similar to that formed by I. obliquus. I. glomeratus causes a canker rot on its host just as I. obliquus does on birch. Rot is usually extensive, and the decay is greater in the upper portions of the tree above the branch stubs. The yellowish-brown conks form on the undersides of down trees or logs.