Phylum Ascomycota Caval.-Sm. (1998) - sac fungi
   Subphylum Pezizomycotina O.E. Erikss. & Winka (1997)
     Class Lecanoromycetes O.E. Erikss. & Winka (1997)
       Subclass Lecanoromycetidae P.M.Kirk, P.F. Cannon, J.C. David & Stalpers ex Miądl., Lutzoni & Lumbsch (2007)
         Order Lecanorales Nannf. (1932)
           Family Parmeliaceae Zenker (1827)
             Genus Letharia (Th.Fr.) Zahlbr. (1892), nom. cons.