Gymnocalycium friedrichii
Gymnocalycium friedrichii in Friciana IV 23: 3. 1964 sec. Kiesling & al. 20141
- ≡Gymnocalycium mihanovichii var. friedrichii in Repert. Spec. Nov. Regni Veg. Sonderbeih. C 29: t. 113. 1936 syn. sec. Kiesling & al. 20141
- =Gymnocalycium mihanovichii var. piraretaense in Kaktusář. Listy 16: 195. 1951 syn. sec. Kew WCVP (2019)2
- =Gymnocalycium friedrichii subsp. tumaemulticostatum in Cactaceae etc. 28: 7. 2018 syn. sec. Metzing 20216
- 6. Metzing, D. 2021: Revisions of Frailea, Gymnocalycium and various other genera. – In: Korotkova N. & al., Cactaceae at Caryophyllales.org – a dynamic online species-level taxonomic backbone for the family. – Willdenowia 51: 251-270. http://doi.org/10.3372/wi.51.51208