Horridocactus marksianus var. tunensis (F.Ritter) Backeb., Cactaceae 6: 3798. 1962
Horridocactus marksianus var. tunensis, Cactaceae 6: 3798. 1962
is new combination for Pyrrhocactus marksianus var. tunensis in Succulenta (Netherlands) 1960: 2. 1960