I don't know what plant it is. Here is a picture of the plant last fall, and maybe you can help me to identify it. Notice that leaves are full of white spots. Would that be fungus? What are bracket fungus?
Looks like a lilac (Syringa). Bracket fungi are a large group of wood decay fungi, named from their usually broad, flat, horizontal, often woody-textured spore bodies. Very common on dead trees, some are also pathogenic on live trees. The amount you have on that stem indicates that if that branch isn't dead already, it soon will be.
