Subspecies, varieties, forms and cultivars of plants belonging to the Gymnocalycium mihanovichii/stenopleurum group

The name Gymnocalycium mihanovichii v. friedrichii was introduced by Werdermann in 1936. Pazout suggested the name G. friedrichii nom. inval. in 1964 but it has not been officially approved. In 1979 Ritter made a description of Gymnocalycium stenopleurum that sometimes can be found under the incorrect name G. mihanovichii v. stenopleurum n. n. (don't confuse it with v. stenogonum). Thus we have 3 taxa: "mihanovichii", "friedrichii" and "stenopleurum". Not taking into account their taxonomic definition they are basic points of the complex with many transitional forms between. These three taxa spread from south to north (North-Western Paraguay): The typical "mihanovichii" inhabits the very south of the area – south and south-east of province Boqueron; "stenopleurum" inhabits a limited area on the very north – in Cerro Leon region and has characteristic recognizable habitus; for "friedrichii" all the area between two mentioned points is indicated.

• Gymnocalycium friedrichii (Werderm.) Pazout: Distingushed from Gymnocalycium miahanovichii for the prevalently purplish pink, wide open flowers and well-pronounced polymorphism of spines. Besides it has tall slender ribs and roller-shaped prominent thickening around areoles.
• Gymnocalycium friedrichii f. cristatum hort.: Crested form with nice stems reddish brown to dark grape coloured.
• Gymnocalycium friedrichii var. moserianum Pazout ex Moser: has brown bodies 2 times larger than G. friedrichii, with sharp ribs striped with white, and only 3 weak spines. Flowers are pale pink and open up entirely. Distribution: Yrebdaque, Boquerón, Paraguay.
• Gymnocalycium mihanovichii (Frič ex Gürke) Britton & Rose: It has wider, lower ribs, in juvenile plants divided into separate chins, in maturity every rib have flat surface and a pleat above each areole. But the essential thing is its pale or brownish-yellow, not fully opening flower.
• Gymnocalycium mihanovichii var. filadelfiense Backeb.
• Gymnocalycium mihanovichii var. stenogonum Frič & Pazout: has larger stem (up to 15 cm in diameter), smooth fresh green to bronze in full sun. The greenish flowers are also larger. Distribution: Toro Alarachii, southern Chaco, Argentina.
• Gymnocalycium mihanovichii cv. Hibotan hort.: chlorophylles mutants, characterized by more or less red coloured bodies.
• Gymnocalycium mihanovichii cv. Hibotan f. cristata hort.: this is the crested form of the chlorophyll-less cv. Hibotan characterized by more or less red coloured bodies.
• Gymnocalycium mihanovichii cv. Nishikii hort.: variegated cultivars only partially de-coloured.
• Gymnocalycium stenopleurum F.Ritter: Distingushed from Gymnocalycium miahanovichii for the white, fully opening flowers. Distribution: Cerro León, Boquerón department of Paraguay.