Distribution: Common in montane conifer forests during spring and summer
Habitat: Spruce, fir, and other mountain conifers
Substrate: duff (sometimes buried)
Spores: spring through early fall
Conservation Status: Not of concern
Fruiting body: golfball- to baseball-sized, round to oval, 3-8 cm broad. Outer and inner layers of peridium adhering to each other, thick (1-5mm) and persistent (not disintegrating); at first smooth and white, but soon becoming graying to brownish an often areolate (cracking to form small scales), the undersurface and cracks white. Sterile base: absent or rudimentary, but a mycelial cord often present. Spore mass: firm and white at first, then yellowish or olive, finally dark brown and powdery (or yellow-brown in one variety);odor often unpleasant ("a combination of sour milk, diesel oil, and pit toilet" - Robert Ramsey).
Sources: Trudell, Steve and Joe Ammirati. Mushrooms of the Pacific Northwest. Portland, Timber Press, Inc. 2009. Arora, David. Mushrooms Demystified. Berkeley, Ten Speed Press, 1986.
PNW Herbaria: Specimen records of Calvatia fumosa in the Consortium of Pacific Northwest Herbaria database
CalPhotos: Calvatia fumosa photos