Phylum Ascomycota Caval.-Sm. (1998) - sac fungi Subphylum Pezizomycotina O.E. Erikss. & Winka (1997) Class Leotiomycetes O.E. Erikss. & Winka (1997) Order Helotiales Nannf. (1932) Family Helotiaceae Rehm (1892), nom. cons. Genus Mytilodiscus Kropp & S.E. Carp. (1984)