Gymnocalycium megalothelon (Sencke ex K. Schumann 1898) Britton & Rose 1922
Paraguay

Gymnocalycium megalothelon из коллекции Олега Балановского (Днепр, Украина). – A plant from the collection of Oleg Balanovsky, Dnipro, Ukraine.
- Gymnocalycium megalothelon ssp. prestleanum H.Till 2005
- Gymnocalycium megalothelon v. susannae H.Till 2005