Gymnocalycium nidulans Backeb., Kaktus-ABC: 293. 1936 ["1935"] Gymnocalycium nidulans Backeb., Kaktus-ABC: 293. 1936 ["1935"]is basionym for Gymnocalycium hossei var. nidulans (Backeb.) H.Till in Gymnocalycium 21 (Sonderausgabe): 816. 2008Taxon for this nameGymnocalycium nidulans Backeb.