Gymnocalycium erolesii Gymnocalycium schroederianum subsp. schroederianum Gymnocalycium platense subsp. schroederianum Gymnocalycium schroederianum subsp. boessii Gymnocalycium schroederianum subsp. paucicostatum Gymnocalycium hyptiacanthum subsp. schroederianum Gymnocalycium hyptiacanthum subsp. paucicostatum Gymnocalycium platense subsp. paucicostatum Gymnocalycium schroederianum subsp. bayense
World Flora Online, http://www.worldfloraonline.org/, accessed June 20, 2024