An emended subgenus Myxacium in the light of a global Cortinarius (Agaricales) phylogeny

Cortinarius subgenus Myxacium has been used since the times of Elias Fries to denote a large group of species characterized by a viscid universal veil. In molecular studies during the past decades, the subgenus was shown to be polyphyletic. In this study, we emend the circumscription of the subgenus, taking into consideration recent research involving taxa from both hemispheres. Known sections of myxacioid taxa are discussed, identifying those that remain in the subgenus and those that do not. A new Myxacium species Cortinarius vitreopallidus from New Zealand is described, and the genus Quadrispora is recombined as a section in Cortinarius subg. Myxacium.