Microscopic characters of Riopa. Riopa metamorphosa, epitype: a subicular hyphae b tube trama and hymenium c anamorph (Sporotrichum aurantiacum) d basidioles and basidia showing the characteristic corymb branching e hymenial cystidia. Spores of f Riopa metamorphosa drawn from the holotype of R. davidii g epitype of R. metamorphosa h holotype of R. pudens.