Fomitopsis mounceae

Fomitopsis mounceae is typically fan-like in shape, with distinct bands usually brown or red in colour.^[1] It can have a resinous, sticky coating.^[1] As the conks age, they often become bumpy or warty.^[1] The cap is 8–25 centimetres (3–10 in) wide and 5–12 cm (2–4+1⁄2 in) thick at the base.^[2]

The underside of the conk is typically white or yellow in colour, with 3–6 round pores per millimetre.^[1] If broken open, the inside is yellowish,^[2] or sometimes woody and brown, with no distinct bands.^[1] It stains brown in KOH.

The spore print is whitish to cream.^[2]

Fomitopsis ochracea is very similar but always lacks a red, orange or yellow zone; F. ochracea chars if burnt, while F. mounceae melts. Fomitopsis schrenkii is found in the Southwest.^[2] Ganoderma applanatum usually lacks a blackish zone on the cap and its pores stain dark brown. Species of Fomes are usually taller than wide.^[2]

The perennial woody conk causes cubical brown rot typical of Fomitopsis. It favours aspen or conifer trees.^[2] It is a detritivore, and does not typically grow on live trees. It typically grows at lower elevations than F. schrenkii.^[1]

It is distributed across Canada and the northern United States, as far south as northern California.^[1]