Caps are 2–8 cm across, strongly convex at first, but mildly flattening over time. They are pale greyish when young, becoming whiter and covered with a semi-translucent and slimy membrane, often with an
ochraceous flush at the centre. The surface layer resembles spore-bearing tissue, with erect club-shaped cells, but lacks functional
basidia (i.e. cap cuticle is hymeniform). The slender stems are 30–100 mm tall and 3–10 mm wide, white striate above a substantial membranous ring and slightly scaly and greyish below. Flesh is thin and white and the
lamellae are
adnate, broad and very distant.
Cystidia are thin-walled cylindric or utriform.
Spore print is white, they are smooth and subglobose in shape and very thickwalled at 13–18×12–15 μm. When porcelain mushrooms grow from the underside of the tree, the stems will curl in a way so the caps are all held horizontally, with the gills facing down.
O. mucida are seldom confused with other fungi. == Distribution and habitat ==