Bolbitius muscicola is a New Zealand endemic member of the Bolbitiaceae distinguished by its brown-spotted, viscid cap, slender pale stipe, and Bolbitius-type spores with a broad germ pore. It is unusual within the genus because it is associated with Nothofagus forest, not grass or dung.

Cap: 10-30 mm across; convex to plano-convex, sometimes slightly depressed. Brown to ochraceous-brown, often with darker spots or patches. Viscid when moist; surface smooth. Margin not strongly striate.
Gills: Free to narrowly attached. Pale at first, becoming rust-brown to ochraceous as spores mature.
Stipe: 30-70 mm x 1.5-3 mm; slender, hollow, fragile. Whitish to pale yellowish, sometimes with fine fibrils. No ring or veil remnants.