Truffle-like, ectomycorrhizal fungi. Hymenogaster-like fungi (lacking a columella, with basal rhizomorphs) characterised as a genus by the cortinarioid spores.

Bougher & Castellano erected a genus Cortinomyces for these fungi, but as it was based on the type of Protoglossum, is a superfluous genus. These authors cited Cunningham (1934) as reporting the species P. luteus from New Zealand, but Cunningham (1944) later treats P. luteus as a synonym of Hymenogaster viscidus, so his concept of this fungus for New Zealand must be doubtful. At least one undescribed species in the genus occurs under Nothofagus in New Zealand.