''Rebutia'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

s in the family

Cactaceae A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek ...

, native to

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

and

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

. They 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 In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projection ...

s. They are considered fairly easy to grow and they may produce large quantities of

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s that germinate freely around the parent plant. The limits of the genus are currently uncertain – in particular whether or not it includes species formerly or currently placed in the genera ''Aylostera'', ''

Cintia ''Rebutia'' is a genus of flowering plants in the family Cactaceae, native to Bolivia and Argentina. They are generally small, colorful cacti, globular in form, which freely produce flowers that are relatively large in relation to the body. They ...

'', ''Sulcorebutia'' and ''

Weingartia '' Weingartia'' is a genus in the family Cactaceae, with species native to Bolivia and Argentina. Distribution Andes mountains of central and south Bolivia and northwest Argentina at elevations of 1600 – 3600 m. Description Plants usua ...

''. The number of species included varies widely from source to source. 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.

Systematics

The genus was designated in 1895 by

Karl Moritz Schumann Karl Moritz Schumann (17 June 1851 – 22 March 1904) was a German botanist. Schumann was born in Görlitz. He was curator of the Botanisches Museum in Berlin-Dahlem from 1880 until 1894. He also served as the first chairman of the ''Deutsc ...

and named after Pierre Rebut (1828–1902), a French cactus nurseryman. The type species is ''R. minuscula'', which has been in cultivation since 1887.

Limits of the genus

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'': Kew's

Plants of the World Online Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...

accepts '' Aylostera'' Speg. and ''

Reicheocactus ''Reicheocactus'', is a monotypic genus of cactus in the family Cactaceae, native to north western Argentina. It has only one known species; ''Reicheocactus famatimensis'' It is usually solitary or slowly clumping and slow growing. The stems are ...

. (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. 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'', and

the Plant List The Plant List was a list of botanical names of species of plants created by the Royal Botanic Gardens, Kew and the Missouri Botanical Garden and launched in 2010. It was intended to be a comprehensive record of all known names of plant species ...

, which separated ''Cintia'', ''Sulcorebutia'' and ''Weingartia'' from ''Rebutia'', but merged ''Aylostera''.

Species

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. E. F. Anderson recognised forty-one species in 2001. The following species are currently accepted:

Phylogeny

Recent research has indicated that the genus ''Rebutia'' as currently defined is polyphyletic. ''Sulcorebutia'' and ''Weingartia'' were kept as separate genera in the study; a summary

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

for those species studied is shown below.. Summary cladogram based on Fig. 2. Species formerly classified as ''Weingartia'', ''Sulcorebutia'' and ''Cintia'' show a close relationship to each other and to species of ''Rebutia'' with naked pericarpels (''Rebutia'' II), including the type species ''R. minuscula''. The larger group of species of ''Rebutia'' studied, those with hairy or bristly pericarpels, form a separate, more distantly related clade (''Rebutia'' I). It is suggested that these be excluded from the genus.

Gallery

''Rebutia II''

File:Rebutia fabrisii 1.jpg, ''Rebutia fiebrigii'' (syn. ''R. fabrisii'') File:Rebutia kariusiana 1.jpg, ''Rebutia kariusiana'' (unresolved name) File:Rebutia padcayensis.jpg, ''Rebutia margarethae'' (syn. ''R. padcayensis'') File:Rebutia krainziana 2.jpg, ''Rebutia marsoneri'' (syn. ''R. krainziana'') File:Rebutia marsoneri pm.JPG, ''Rebutia marsoneri'' – first known species with yellow flower File:Rebutia minuscula4.jpg, ''Rebutia minuscula'' – first discovered ''Rebutia'' File:Rebutia grandiflora 1.jpg, ''Rebutia minuscula'' f. ''grandiflora'' – form with largest flower File:Rebutia_senilis_1.jpg, ''Rebutia minuscula'' (syn. ''R. senilis'') – form with orange red flower File:Rebutia senilis lilacino-rosea 1.jpg, ''Rebutia minuscula'' (syn. ''R. senilis'') – form with rose flower File:Rebutia chrysacantha kesselringiana 1.jpg, ''Rebutia minuscula'' (syn. ''R. chrysacantha'') – form with yellow flower File:Rebutia violaciflora 1.jpg, ''Rebutia minuscula'' (syn. ''R. violaciflora'') – form with violet flower

''Rebutia I - Aylostera, Mediolobivia''

File:Rebutia albiflora 1.jpg, ''Rebutia albiflora'' Smallest species with white flowers. ''Aylostera''. File:Rebutia narvaecensis 1.jpg, ''Rebutia narvaecensis'' popular for pink flowers. ''Aylostera''. Image:Rebutia muscula.JPG, ''Rebutia muscula'' with white spination. Image:R heliosa.jpg, ''Rebutia heliosa''. ''Aylostera''. Image:Rebutia einsteinii 1.jpg, ''Rebutia einsteinii'' grow up to elevation 5000 m. ''Mediolobivia''. Image:Mediolobivia eucaliptana.jpg, ''Rebutia pygmaea'' one of the oldest species. ''Mediolobivia''. File:Rebutia knizei 006.JPG, ''Rebutia knizei'' has yellow flowers with green stoma. ''Mediolobivia''. File:Rebutia torquata 1.jpg, ''Rebutia torquata'' with radial spines. ''Mediolobivia''. File:Rebutia pauciareolata 1..jpg, ''Rebutia pauciareolata'' File:Rebutia 787.JPG, Minicollection on the window. File:Rebutia perplexa.jpg, Great clusters of old plants. ''Rebutia perplexa''. File:Rebutia cajasensis 1.JPG, ''Rebutia heliosa'' var. ''cajasensis''

Notes and references

External links

*
''Rebutia'' — Names and Identification

Cactiguide.com: ''Rebutia''
{{Taxonbar, from=Q310441 Cacti of South America Flora of Argentina Flora of Bolivia Cactoideae genera