Phylum Ascomycota Caval.-Sm. (1998) - sac fungi Subphylum Pezizomycotina O.E. Erikss. & Winka (1997) Class Leotiomycetes O.E. Erikss. & Winka (1997) Order Rhytismatales M.E.Barr ex Minter (1986) Family Rhytismataceae Chevall. (1826), nom. cons. Genus Bivallium O.E. Erikss. & D.Hawksw. (1993), orth. inval. see Genus Bivallum P.R. Johnst. (1991)