Gymnocalycium

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Gymnocalycium

Gymnocalycium Pfeiff. ex Mittler, Taschenb. Cactuslieb. 2: 124. 1844 sec. Demaio & al. 20111
  • 1. Demaio, P., Barfuss, M. H. J., Kiesling, R., Till, W. & Chiapella, J. 2011: Molecular phylogeny of Gymnocalycium (Cactaceae): assessment of alternative infrageneric systems, a new subgenus, and trends in the evolution of the genus. – American Journal of Botany 98(11): 1841-1854. http://doi.org/10.3732/ajb.1100054
  • 2. Demaio, P., Barfuss, M. H. J., Kiesling, R., Till, W. & Chiapella, J. 2011: Molecular phylogeny of Gymnocalycium (Cactaceae): assessment of alternative infrageneric systems, a new subgenus, and trends in the evolution of the genus. – American Journal of Botany 98(11): 1841-1854. http://doi.org/10.3732/ajb.1100054

Notes

Phylogenetics: Found as monophyletic at first by Ritz & al. (2007), then studied in more detail and confirmed as monophyletic by Meregalli & al. (2010). Taxonomy: Demaio & al. (2011) conducted the most detailed phylogenetic study by sampling almost the whole genus and again confirmed the monophyly of Gymnocalycium with maximal support.
Several infrageneric classifications have been proposed, based mainly on size, form and surface characters of the seeds, but corresponding with flowers and fruits characters, too (see Demaio & al. 2011 for an overview). Seven subgenera have been accepted by Demaio & al. (2011). The type bearing subgenus (Gymnocalycium subg. Gymnocalycium) represents the most recent clade within the genus. Many of the “new” taxa described in the last two decades belong to this subgenus. Distinction of the taxa belonging to it based on morphological or molecular data is often almost impossible, which may reflect a rapid and recent radiation (Demaio & al. 2011, Řepka & Mracek 2012). There is evidence for different ploidy levels and hybridization (Řepka 2015), but the taxonomy of this subgenus remains poorly understood.
Key literature: Illustrated synopsis by Charles (2009). Nomenclature: Published as "Gymnocalicium". A nomenclatural checklist of names prior to 1995 was provided by Metzing & al. (1995). A

Taxon standing

Category B. The genus is monophyletic based on phylogenetic studies that support the clade based on a sufficiently dense or even complete sampling, or support a monotypic genus as a distinct lineage, but do not provide a new taxonomic treatment at the species level. In many cases, older classical taxonomic synopses or a monographic treatment exist for these genera providing a reliable assessment of the species included.

Acknowledgments

Revised by Detlev Metzing

Bibliography

A. Metzing, D. 2021: Revisions of Frailea, Gymnocalycium and various other genera. – In: Korotkova N. & al., Cactaceae at Caryophyllales.org – a dynamic online species-level taxonomic backbone for the family. – Willdenowia 51: 251-270. http://doi.org/10.3372/wi.51.51208