Rebutia

There has been considerable debate about the extent of the genus. In the middle of the twentieth century there was a tendency to separate groups of plants within Rebutia as new genera, e.g. Mediolobivia, whereas towards the end of the century the reverse tendency predominated, with genera previously regarded as separate, such as Weingartia, being subsumed within Rebutia. At the beginning of the twenty-first century there was a broad consensus, as reflected in Kew's list of Vascular Plant Families and Genera, that the following genera should be regarded as synonyms of Rebutia:[4]

(The generic names Bridgesia, Spegazzinia, Echinorebutia, Eurebutia, Mediorebutia, Neogymnantha and Setirebutia are invalid, the first two because they are homonyms of Bridgesia Bert. ex Cambess. and Spegazzinia Saccardo respectively, the remainder for lack of any valid publication. Some of these are nevertheless valid names for subdivisions of the genus.)

The history of the taxonomic treatment of the genera Rebutia, Aylostera, Weingartia, Sulcorebutia and Cintia is summarized below.[5]

The variation in the treatment of the genus is illustrated by the difference between Mosti et al., who in 2011 treated Aylostera and Weingartia (including Cintia and Sulcorebutia) as distinct from Rebutia,[5] and the Plant List, which as of March 2013 separated Cintia, Sulcorebutia and Weingartia from Rebutia, but merged Aylostera.[6]

The number of species is similarly debatable, because of disagreement both over what constitutes the genus and what constitutes a species. A very large number of plants that have circulated as species of Rebutia are now generally regarded as varieties, forms or synonyms of others.[7] E. F. Anderson recognised forty-one species in 2001.[8] The following species are currently accepted:[9]

• 
  Rebutia fiebrigii (syn. R. fabrisii)
• 
  Rebutia kariusiana (unresolved name)
• 
  Rebutia margarethae (syn. R. padcayensis)
• 
  Rebutia marsoneri (syn. R. krainziana)
• 
  Rebutia marsoneri – first known species with yellow flower
• 
  Rebutia minuscula – first discovered Rebutia
• 
  Rebutia minuscula f. grandiflora – form with largest flower
• 
  Rebutia minuscula (syn. R. senilis) – form with orange red flower
• 
  Rebutia minuscula (syn. R. senilis) – form with rose flower
• 
  Rebutia minuscula (syn. R. chrysacantha) – form with yellow flower
• 
  Rebutia minuscula (syn. R. violaciflora) – form with violet flower

• 
  Rebutia albiflora Smallest species with white flowers. Aylostera.
• 
  Rebutia narvaecensis popular for pink flowers. Aylostera.
• 
  Rebutia muscula with white spination.
• 
  Rebutia heliosa. Aylostera.
• 
  Rebutia einsteinii grow up to elevation 5000 m. Mediolobivia.
• 
  Rebutia pygmaea one of the oldest species. Mediolobivia.
• 
  Rebutia knizei has yellow flowers with green stoma. Mediolobivia.
• 
  Rebutia torquata with radial spines. Mediolobivia.
• 
  Rebutia pauciareolata
• 
  Minicollection on the window.
• 
  Great clusters of old plants. Rebutia perplexa.
• 
  Rebutia heliosa var. cajasensis