Found on tree species such as grand fir (and indicating a rotten core).

[2] Growing to 8–20 centimetres (3–8 in) wide,[3] it can be identified by the grayish spines of its lower surface.

[3] Similar species include the rare Echinodontium ballouii, as well as various conks which have pores rather than teeth below.

[2] Some Plateau Indian tribes applied the fungus to skin to prevent it from chapping.

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