Rebutia
Encyclopedia
Rebutia K. Schum. is a genus
in the family Cactaceae
, native to Bolivia
and Argentina
.
It was designated in 1895 by Karl Moritz Schumann
and named after Pierre Rebut (1828-1898), a French cactus nurseryman. The type species is R.minuscula, which has been in cultivation since 1887. These 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 tubercle
s. They are considered fairly easy to grow and they may produce large quantities of seed
s 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 Saccardo respectively, the remainder for lack of any valid publication. Some of these are nevertheless valid names for subdivisions of the genus.)
However, more recent research has indicated that the genus Rebutia so defined is polyphyletic: species formerly classified as Weingartia, Sulcorebutia and Cintia Kníže & Říha show a close relationship to each other and to species of Rebutia with naked pericarpels, including the type species R.minuscula, and it is proposed that they should be retained within the genus. However, species with hairy or bristly pericarpels form a separate, more distantly related clade and it is proposed that these should be excluded. The latter should presumably now be reclassified as Aylostera.
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 plants that that have circulated as species of Rebutia are now generally regarded as varieties, forms or synonyms of others. E. F. Anderson recognised forty-one species.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
in the family Cactaceae
Cactus
A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...
, native to Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
and Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
.
It was designated in 1895 by Karl Moritz Schumann
Karl Moritz Schumann
Karl Moritz Schumann was a German botanist.Dr. Schumann was the curator of the Botanisches Museumin Berlin-Dahlem from 1880 until 1894...
and named after Pierre Rebut (1828-1898), a French cactus nurseryman. The type species is R.minuscula, which has been in cultivation since 1887. These 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 tubercle
Tubercle
A tubercle is generally a wart-like projection, but it has slightly different meaning depending on which family of plants or animals it is used to refer to....
s. They are considered fairly easy to grow and they may produce large quantities of seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s that germinate freely around the parent plant.
Synonymy
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 the list of Vascular Plant Families and Genera maintained at the Royal Botanic Gardens, Kew, that the following genera should be regarded as synonyms of Rebutia:- Aylostera Speg.
- Bridgesia Backeb.
- Cylindrorebutia FricAlberto Vojtech FricAlberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
& Kreuz. - Digitorebutia FricAlberto Vojtech FricAlberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
& Kreuz. - Echinorebutia FricAlberto Vojtech FricAlberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
- Eurebutia FricAlberto Vojtech FricAlberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
- Gymnantha Y.Itô
- Mediolobivia Backeb.
- Mediorebutia FricAlberto Vojtech FricAlberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
- Neogymnantha Y.Itô
- Reicheocactus Backeb.
- Setirebutia FricAlberto Vojtech FricAlberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
& Kreuz. - Spegazzinia Backeb.
- Sulcorebutia Backeb.
- Weingartia Werderm.
(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.)
However, more recent research has indicated that the genus Rebutia so defined is polyphyletic: species formerly classified as Weingartia, Sulcorebutia and Cintia Kníže & Říha show a close relationship to each other and to species of Rebutia with naked pericarpels, including the type species R.minuscula, and it is proposed that they should be retained within the genus. However, species with hairy or bristly pericarpels form a separate, more distantly related clade and it is proposed that these should be excluded. The latter should presumably now be reclassified as Aylostera.
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 plants that that have circulated as species of Rebutia are now generally regarded as varieties, forms or synonyms of others. E. F. Anderson recognised forty-one species.
Further reading
- Cacti , Succulents and Tropical Plants edited by Nicky Hayden. Marshall Cavendish Ltd, (1980).
- Rebutia Names and Identity
- The species list is compiled from cactiguide.com, which is in turn referenced from several books which are listed on that site. The principal book listed there is The Cactus Family by Edward F. Anderson, (2001).