Product Code Database
Rebutia is a genus of in the family cactus, native to Bolivia and Argentina. The limits of the genus have varied widely, depending on whether genera such as Aylostera and Weingartia are included or treated separately. , Plants of the World Online accepted only three species of Rebutia. A very large number of plants that have been treated in cultivation as species of Rebutia are now generally regarded as varieties, forms or synonyms of a much smaller number of species, or have been transferred to other genera. Plants treated as Rebutia are generally small, colorful cacti, globular in form, which freely produce flowers that are relatively large in relation to the body. They have no distinctive ribs, but do have regularly arranged small . They are considered fairly easy to grow and they may produce large quantities of that germinate freely around the parent plant.
(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 Backeb. 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.
| Rebutia |
| Digitorebutia, Cylindrorebutia, Echinorebutia, Setirebutia, Hymenorebutia, Scopaerebutia |
| Rebutia |
| Aylostera subg. Aylostera |
| Aylostera subg. Mediolobivia |
| Weingartia |
| Weingartia incl. Cintia |
The variation in the treatment of the genus is illustrated by the difference between Anderson in 2001, who synonymized genera including Aylostera and Weingartia with Rebutia, thereby creating a genus with as many as 41 species, and Mosti et al., who in 2011 separated Aylostera and Weingartia (including Cintia and Sulcorebutia) from Rebutia. , Plants of the World Online agreed with Mosti et al. in keeping Aylostera separate, and also merged Cintia and Sulcorebutia into Weingartia, resulting in Rebutia having only three species.
Species formerly classified as Weingartia, Sulcorebutia and Cintia showed a close relationship to each other and to species of Rebutia with naked pericarpels ( Rebutia II above), including the type species R. minuscula. The larger group of species of Rebutia studied, those with hairy or bristly pericarpels, formed a separate, more distantly related clade ( Rebutia I). It was suggested that these be excluded from the genus, and , Plants of the World Online placed them in the genus Aylostera.
Phylogeny
Molecular phylogenetic studies showed that when broadly circumscribed, the genus Rebutia was polyphyletic. Sulcorebutia and Weingartia were kept as separate genera in a 2007 study whose summary cladogram for those species studied is shown below.. Summary cladogram based on Fig. 2.
Species
The number of species has been debated, 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.Cf. the list of approximately two hundred names under Rebutia (not to mention those given under other genera) provided in B. Fearn and L. Pearcy, The Genus Rebutia, 1895-1981, Matlock: Abbey Brook, 1981, pp.60-71. E. F. Anderson recognised 41 species in 2001.Edward F. Anderson, The Cactus Family, Portland, Oregon: Timber Press, 2001, pp.599-611. Only the following three species were accepted by Plants of the World Online .
Argentina Argentina Bolivia to Argentina (Salta)
Gallery
Notes and references
External links
|
|
