Origin and Habitat: Rio Grande do Sul, Brazil.

• Gymnocalycium horstii subs. buenekeri (Swales) P.J.Braun & Hofacker
• Gymnocalycium buenekeri Swales
• Gymnocalycium horstii var. buenekeri (Buining)

• Gymnocalycium horstii Buining
• Gymnocalycium horstii subs. megalanthum Amerh.

• Gymnocalycium horstii subs. buenekeri (Swales) P.J.Braun & Hofacker
• Gymnocalycium buenekeri Swales
• Gymnocalycium horstii var. buenekeri (Buining)

Description: Gymnocalycium buenekeriSN|18875]]SN|18878]] was originally published as a variety of Gymnocalycium horstiiSN|18878]]SN|18875]], but the description was technically invalid. However the two species are very similar, both have very similar great pink flowers and the same (usually) five ribbed appearance, and good, yellow spines. It can clumps and is quick to grow.

Bibliography: Major references and further lectures
1) Edward Anderson “The Cactus family” Timber Press, Incorporated, 2001
2) James Cullen, Sabina G. Knees, H. Suzanne Cubey "The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass" Cambridge University Press, 11/Aug/2011
3) David R Hunt; Nigel P Taylor; Graham Charles; International Cactaceae Systematics Group. "The New Cactus Lexicon" dh books, 2006
4) Larocca, J. & Machado, M. 2013. Gymnocalycium horstii. In: IUCN 2013. "IUCN Red List of Threatened Species." Version 2013.2. <www.iucnredlist.org>. Downloaded on 17 February 2014.

Cultivation and Propagation: Very easy to grow, this plants offers no cultivation difficulties. Summer grower needs moderate to copious waterings in summer. Quite frost resistant if kept dry in winter -4° C. Feed with a high potassium fertilizer in summer. Sun Exposure: Full sun to light shade.
Propagation: Seeds (seldom produces offsets)