Pyrrhocactus dubius Backeb., Kaktus-ABC: 415. 1936 ["1935"] Pyrrhocactus dubius Backeb., Kaktus-ABC: 415. 1936 ["1935"]is basionym for Neoporteria dubia (Backeb.) Donald & G.D.Rowley in Cact. Succ. J. Gr. Brit. 28: 56. 1966Taxon for this namePyrrhocactus dubius Backeb.