Ritterocereus griseus (Haw.) Backeb. in Cact. Succ. J. (Los Angeles) 23: 121. 1951 Ritterocereus griseus (Haw.) Backeb. in Cact. Succ. J. (Los Angeles) 23: 121. 1951is new combination for Cereus griseus Haw., Syn. Pl. Succ.: 182. 1812Taxon for this nameRitterocereus griseus (Haw.) Backeb.