Fruiting body annual, typically stipitate on the ground from roots of trees; usually compound, composed of several circular to irregularly lobed caps up to 25 cm broad; flesh soft when fresh, tough in age; surface densely hairy, smoother in age; color variable, cream to ochraceous, to yellow or green-yellow when fresh, rusty-brown to dark brown in age; staining brown to black; flesh yellowish-brown, becoming dark rusty brown in age.
Tube layer decurrent, greenish to rusty brown, up to 1.5 cm thick.
Spores 7-8 x 20-25 µm, ellipsoid to ovoid, hyaline, smooth.
Solitary to gregarious near conifers, especially pine and Douglas fir; lignicolous, but usually appearing terrestrial; fruiting in the fall, but persisting throughout the season.
Phaeolus schweinitzii causes a brown cubical rot of the heartwood of butt and roots of living conifers. Although abhorred by foresters, it is highly esteemed by dye-makers for coloring yarn.