bracket fungus

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of various fungi that form shelflike growths on tree trunks and wood structures.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any of various fungi of the family Polyporaceae, whose fruiting bodies form on trees and resemble shelves.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a woody fungus that forms shelflike sporophores on tree trunks and wood structures