Cactus jansenianus (Backeb.) Borg, Cacti, ed. 1: 279. 1937 Cactus jansenianus (Backeb.) Borg, Cacti, ed. 1: 279. 1937is new combination for Melocactus jansenianus Backeb. in Blätt. Kakteenf. 1935(2): 2. 1935Taxon for this nameCactus jansenianus (Backeb.) Borg