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 ...
of
cactus
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 ...
Mammillaria
''Mammillaria'' is one of the largest genera in the cactus family (Cactaceae), with currently 200 known species and varieties recognized. Most of the mammillaria are native to Mexico, but some come from the southwest United States, the Caribbea ...
'', but
molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
studies have shown that when broadly
circumscribed
In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius.
Not every polyg ...
, ''Mammillaria'' is not
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
, and ''Cochemiea'' has been accepted as a separate genus.
Taxonomy
A 2021
molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
study of the "mammilloid clade", which included the genera ''Cochemiea'', ''Coryphantha'', ''Cumarinia'', ''Escobaria'', ''Mammillaria'', ''Neolloydia'' and ''Ortegocactus'', showed that it consisted of four
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
Mammillaria
''Mammillaria'' is one of the largest genera in the cactus family (Cactaceae), with currently 200 known species and varieties recognized. Most of the mammillaria are native to Mexico, but some come from the southwest United States, the Caribbea ...
'', with a reduced number of species; ''
Coryphantha
''Coryphantha'' (from Greek, "flowering on the top"), or beehive cactus, is a genus of small to middle-sized, globose or columnar cacti. The genus is native to arid parts of Central America, Mexico, through Arizona, New Mexico, and western Texas ...
'', expanded to include species previously placed in ''Mammillaria'' and ''Escobaria''; and ''Cochemiea'', expanded to include a large number of species previously placed in ''Mammillaria'', as well as ''Neolloydia conoidea''.
Species
In 2021, Breslin, Wojciechowski and Majure placed the following species in the genus, some already placed there and some moved from ''Mammillaria'', ''Neolloydia'', ''Neomammillaria'' and ''Ortegocactus''. ,
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 ...
accepted in the genus the species moved by Breslin et al.