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<a href="http://www.fcps.edu/StratfordLandingES/Ecology/mpages/artists_conk.htm">Ganoderma applanatum</a>.
Common Name: Artist's Conk
Artist's Conk is a large polypore, also called a "shelf mushroom." Polypores are wide and flat, and they usually grow on tree trunks or on the sides of stumps and fallen logs.
Artist's Conk can grow up to 20 inches wide. They have a woody feel and are rough and horny. Usually, they are fairly flat, but sometimes they are hoof-shaped.
These fungi are gray to brownish in color, but can be green when covered with algae or moss. Artist's Conks grow year-round. You can discover how old they are the same way you can a tree. By cutting it in half, you can count layers. Each layer represents a year.
Artist's Conk can grow by itself or in small groups. They grow on dead wood, and sometimes on wounds in living trees. When it grows on living trees it is a parasite. This fungi weakens the wood it grows on, making places for insects and woodpeckers to start holes.
This fungi gets its name because when you flip it over you can carve writing or pictures in it. The picture will stay in the fungus and cannot be erased.
So inedible, but you can use it for graffiti.