Phellinus igniarius

Phellinus igniarius (syn. Phellinus trivialis) is a fungus of the family Hymenochaetaceae. Like other members of the genus of Phellinus it lives by saprotrophic nutrition, in which the lignin and cellulose of a host tree is degraded and is a cause of white rot. Common names are willow bracket and fire sponge.

The fungus forms perennial fruiting bodies that rise as woody-hard, hoof or disc-shaped brackets from the bark of the infested living tree or dead log. The tree species is often willow but it may be commonly found on birch and alder and other broad leafed trees. The top is covered with a dark, often cracked crust, a stem is present only in its infancy. Unlike most fungi it has a hard woody consistency and may persist for many years, building a new surface layer each year. It was prized as kindling material. In Alaska, it is burnt by locals, and the ash (punk ash) is mixed with chewing tobacco to enhance the effect of the nicotine in the tobacco.