Q: I recently had two large black locust trees cut down. They had shelf fungi (conks) growing on the trunks. A friend of the ax man wanted the conks. Do you have any idea what uses one would have for these?

A: I don’t know why they wanted the conks, other than for decoration. Artist’s conk, Ganoderma applanatum, is not the same fungus. This fungus has a very smooth underside, which generations of artists have used to apply their handiwork. The shelf fungus you had, Phellinus robiniae, is not the same thing but might be used similarly.