Gymnocalycium castellanosii subsp. castellanosii sec. Charles 2009
- =Gymnocalycium bozsingianum Schütz in Kaktusy (Brno) 13: 124. 1977 syn. sec. Charles 2009
- ≡Gymnocalycium castellanosii var. bozsingianum (Schütz) Piltz in Gymnos 9(18): 43. 1993 syn. sec. Charles 2009
- ≡Gymnocalycium castellanosii subsp. bozsingianum (Schütz) Amerh. & H.Till in Gymnocalycium 19: 675. 2006 syn. sec. Charles 2009
- =Gymnocalycium castellanosii var. armillatum Piltz in Gymnos 9(18): 48. 1993 syn. sec. ???
- ≡Gymnocalycium castellanosii subsp. armillatum (Piltz) Papsch in Cactus & Co. 12: 200. 2008 syn. sec. Charles 2009
- =Gymnocalycium castellanosii var. rigidum H.Till in Gymnocalycium 19: 670. 2006 syn. sec. Kew WCVP (2019)
- =Gymnocalycium castellanosii var. spinosior Milt in Cactaceae etc. 30: 46. 2020 syn. sec. Metzing 2021