Gymnocalycium reductum
Gymnocalycium reductum, Taschenb. Cactuslieb. 2: 124. 1844 sec. Charles 20091
- =Echinocactus reductus in Monatsschr. Kakteenk. 5: 107. 1895 syn. sec. Metzing 20215
- 5. 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
- =Echinocactus fennellii, Gesamtbeschr. Kakt.: 409. 1897–1899 syn. sec. Metzing 20216
- ≡Echinocactus gibbosus var. fennellii in Monatsschr. Kakteenk. 9: 115. 1899 syn. sec. Metzing 20216
- ≡Echinocactus gibbosus f. fennellii, Handb. Kakteenkult.: 186. 1907 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