A large, tiered, shelf-forming fungus on living hardwoods, especially maple and beech, whose undersides are covered with crowded white spines rather than pores. It is a parasite and a common cause of heart rot, often fruiting from wounds high on the trunk. The overlapping whitish to cream shelves can build into clusters up to 80 cm tall and persist for weeks.
Northeastern North America, from southern Canada south to Kentucky and west to the Great Plains.
Characteristics
Caps: semicircular to kidney-shaped shelves up to 30 cm wide and 2.5-5 cm thick at the base, fused in overlapping clusters up to 80 cm high. Surface hairy to rough, sometimes zoned, whitish to creamy yellow, turning yellow-brown, sometimes greenish from algae. Underside: crowded whitish spines about 1 cm long (to 2 cm), with ragged tips, yellowing with age. Flesh: tough, fibrous. Odor: not distinctive when young; old specimens smell like spoiled ham. Taste: not distinctive when young, becoming bitter.
