Subspecies, varieties, forms and cultivars of plants belonging to the Gymnocalycium hossei group

• Gymnocalycium guanchinense Schütz: has a dark red-violet-brown stems with chin humps below the large woolly areoles. The spines are pale brown extremely curved and long. Distribution: Argentina (La Rioja).
• Gymnocalycium hossei A.Berger
• Gymnocalycium hossei var. breviflorum (Backeb.) H.Till
• Gymnocalycium hossei var. crassispinum Y.Itô
• Gymnocalycium hossei var. nidulans (Backeb.) H.Till: has a dense covering of stout grey interlacing spines. The plants typically got a dull brownish-green body colour. Distribution: La Rioja, Argentina.
• Gymnocalycium mazanense (Backeb.) Backeb.: has dull-green to brownish stems. Central spine 1. Radial spines 7-9 spreading, curving backward, one pointing downward up to 1,5 cm long. Distribution: a Rioja and Catamarca, Argentina.
• Gymnocalycium mazanense var. ferox Backeb.: distinguishes for the covering of very stout greyish interlacing spines. The body is almost concealed by the spines. Distribution: La Rioja, Argentina.
  
• Gymnocalycium rhodantherum (Boed.) H.Till
• Gymnocalycium rhodantherum var. cinerascens H.Till
• Gymnocalycium rhodantherum subs. recii (Boed.) Milt
• Gymnocalycium weissianum Backeb. in Backeb. & F.M.Knuth: distinguishes for the covering of stout bright greyish-white interlacing spines. Distribution: La Rioja and Catamarca, Argentina
• Gymnocalycium weissianum var. atroroseum Backeb. in Backeb. & F.M.Knuth