A wood-rotting fungus. Fertile surface, from which the spores are released, forms a crust over the surface of the wood, a growth form called corticioid. May also extend outward from the sides of the corticioid portion. Fertile surface reddish brown, wrinkled, often with white outline. Upper, non-fertile surface (if projecting), similar in color, zoned, sometimes hairy.

Not often seen since it usually grows on the undersurface of branches and twigs (the branch in the picture was turned over).

There are other brown crusts, so identification must be tentative if found. If you search under fallen branches for it, you may find other colorful corticioids like Cobalt Crust (Pulcherricium caeruleum), Red and Yellow Crust (Phlebia coccineofulva) and Wrinkled Crust (Phlebia radiata).