bracket fungus (shelf fungus) Any of a large family (Polyporaceae) of common arboreal fungi that have spore-bearing tubes under the cap. Bracket fungi are usually hard and leathery or wood-like and have no stems. They often cover old logs and their parasitic activity may kill living trees. Some are edible when young.

bracket fungus Any one of a large group of fungi (order Aphyllophorales), many of which produce fruiting bodies that project from the trunks of trees. Heterobasidion annosum (Fomes annosus) is a parasite of coniferous trees that is the principal cause of decay in conifers.

bracket fungus Any one of a large group of fungi (order Aphyllophorales), many of which produce fruiting bodies that project from the trunks of trees. Heterobasidion annosum (Fomes annosus) is a parasite of coniferous trees that is the principal cause of decay in conifers.