Taxonomy of the Cactaceae

Introduction

The classification of the family Cactaceae remains uncertain as of March 2012. Since the mid-1990s, the system produced by the International Cactaceae Systematics Group (ICSG) of the International Organization for Succulent Plant Study has been used as the basis of many published classifications. Detailed treatments produced in the 21st century have divided the family into around 125–130 genera and 1,400–1,500 species, which are then arranged into a number of tribes and subfamilies.

The ICSG classification of the family recognizes four subfamilies: Pereskoideae (consisting only of the genus Pereskia), Opuntioideae, Maihuenioideae (consisting only of the genus Maihuenia) and Cactoideae. Molecular phylogenetic studies suggest that Pereskia is not monophyletic (i.e. its species are not the complete set of descendants of a common ancestor), although the three other subfamilies are. The Bayesian consensus cladogram from a 2005 study is shown below:

Five tribes have been recognized within the subfamily Opuntioideae: Tephrocacteae, Pterocacteae, Austrocylindropuntieae, Cylindropuntieae and Opuntieae. All but the first, Tephrocacteae, were shown to be "essentially monophyletic" in molecular phylogenetic study in 2009. A summary of the consensus Bayesian tree is shown below (tribes are bold; the number of species in the study is shown in parentheses).

Many of the genera within the Opuntioideae are not monophyletic. Maihueniopsis is highly polyphyletic, appearing in four separate lineages. The two largest genera within the subfamily, Opuntia and Cylindropuntia are also not monophyletic. The classification of the Opuntioideae is thus uncertain as of March 2012; Griffith and Porter say that changes in classification will require "broad information (of multiple data types) regarding all species of opuntioid cacti".

The ICSG classification divides the subfamily Cactoideae into nine tribes. However, phylogenetic research has not supported most of these tribes, nor even the genera of which they are composed. A 2011 study found that "an extraordinarily high proportion of genera" were not monophyletic, including 22 (61%) of the 36 genera in the subfamily Cactoideae sampled in the research. Of the nine tribes recognized within Cactoideae, one, Calymmantheae, comprises a single genus, Calymmanthium. Of the remaining eight, only two (Cacteae and Rhipsalideae) have been shown to be monophyletic. A summary of the cladograms for the Cactoideae presented in a 2011 paper is shown below (ICSG tribes in bold).

The classification of genera and tribes in the Cactaceae is thus likely to change in future.

Classification

Unless otherwise indicated, the subfamily placement of the genera listed here is based on Anderson's 2001 presentation of the ICSG classification, as is the tribal placement of the genera of the subfamily Cactoideae. The division of the subfamily Opuntioideae into tribes is additional to the ICSG system.

Subfamily Pereskioideae

Pereskia Mill.

synonyms: Peirescia Zucc. (orth. var.), Peireskia Steud. (orth. var.), Perescia Lem. (orth. var.), Rhodocactus (A.Berger) F.M.Knuth

Tribe Austrocylindropuntieae

Austrocylindropuntia Backeb.

Cumulopuntia F.Ritter

Tribe Cylindropuntieae

Cylindropuntia (Engelm.) F.M.Knuth – chollas

Grusonia F.Rchb. ex Britton & Rose

including Corynopuntia F.M.Knuth, Micropuntia Daston

Pereskiopsis Britton & Rose

synonyms: Peireskiopsis Vaupel (orth. var.)

Quiabentia Britton & Rose

Tribe Opuntieae

Brasiliopuntia (K.Schum.) A.Berger

Consolea Lem.

Miqueliopuntia Fric ex F.Ritter

Opuntia Mill. – prickly pears

synonyms:Airampoa Fric, Cactodendron Bigelow, nom. inval., Cactus Lem., Chaffeyopuntia Fric & Schelle, Clavarioidia Kreuz. (nom. inval.), Ficindica St.-Lag., Nopalea Salm-Dyck, Parviopuntia Soulaire & Marn.-Lap. (nom. inval.), Phyllarthus Neck. ex M.Gómez (nom. inval.), Salmiopuntia Fric (nom. inval.), Subulatopuntia Fric & Schelle, Tunas Lunell, Weberiopuntia Fricincluding Nopalea Salm-Dyck

Tacinga Britton & Rose

Tunilla D.R.Hunt & Iliff

Tribe Pterocacteae

Pterocactus K.Schum.

Tribe Tephrocacteae

Maihueniopsis Speg.

including Puna R.Kiesling

Tephrocactus Lem.

synonyms: Pseudotephrocactus Fric

Subfamily Maihuenioideae

Maihuenia (Phil. ex F.A.C.Weber) K.Schum.

Tribe Browningieae

Armatocereus Backeb.

Browningia Cárdenas, Gymnocereus Rauh & Backeb.

Jasminocereus Britton & Rose

Neoraimondia Britton & Rose

synonyms: Neocardenasia Backeb.

Stetsonia Britton & Rose

Tribe Cacteae

Acharagma (N.P.Taylor) Glass

AriocarpusScheidw. – living rock

synonyms: Anhalonium Lem., Neogomesia Castañeda, Neogomezia Buxb. (orth. var.), Roseocactus A.Berger, Stromatocactus Karw. ex Rümpler (nom. inval.)

Astrophytum Lem.

synonyms: Astrophyton Lawr. (orth. var.), Maierocactus E.C.Rost

Aztekium Boed.

Cochemiea (K.Brandegee) Walton – see Mammillaria

Coryphantha (Engelm.) Lem. – beehive cactus

synonyms: Aulacothele Monv. (nom. inval.), Cumarinia Buxb., Glandulifera (Salm-Dyck) Fric, Lepidocoryphantha Backeb., Roseia Fric (nom. inval.)

Echinocactus Link & Otto – barrel cactus

synonyms: Brittonrosea Speg., Echinofossulocactus Lawr., Homalocephala Britton & Rose

Echinomastus Britton & Rose

Epithelantha F.A.C.Weber ex Britton & Rose – pingpong ball cactus

Escobaria Britton & Rose – foxtail cactus, pincushion cactus

synonyms: Cochiseia W.H.Earle, Escobesseya Hester, Fobea Fric (nom. inval.), Neobesseya Britton & Rose

Ferocactus Britton & Rose – barrel cactus

synonyms: Bisnaga Orcutt, Brittonia C.A.Armstr. (nom. inval.)

Geohintonia Glass & W.A.Fitz Maur.

Leuchtenbergia Hook.

Lophophora J.M.Coult. – peyote

Mammillaria Haw. – fishhook cactus, globe cactus, pincushion cactus, bird's-nest cactus

synonyms: Bartschella Britton & Rose, Cactus L., Chilita Orcutt, Cochemiea (K.Brandegee) Walton, Dolichothele (K.Schum.) Britton & Rose, Ebnerella Buxb., Haagea Fric, Krainzia Backeb., Lactomammillaria Fric (nom. inval.), Leptocladia Buxb., Leptocladodia Buxb., Mamillaria F.Rchb. (orth. var.), Mamillopsis (E.Morren) F.A.C.Weber ex Britton & Rose, Mammariella Shafer (nom. inval.), Mammilaria Torr. & A.Gray (orth. var.), Neomammillaria Britton & Rose, Oehmea Buxb., Phellosperma Britton & Rose, Porfiria Boed., Pseudomammillaria Buxb., Solisia Britton & Rose

Mammilloydia Buxb.

Neolloydia Britton & Rose

synonyms: Napina Fric (nom. inval.), Pseudosolisia Y.Itô (nom. inval.)

Obregonia Fric

Ortegocactus Alexander

Pediocactus Britton & Rose – hedgehog cactus

synonyms: Navajoa Croizat, Pilocanthus B.W.Benson & Backeb.

Pelecyphora C.Ehrenb.

synonyms: Encephalocarpus A.Berger

Sclerocactus Britton & Rose – fishhook cactus

synonyms: Ancistrocactus Britton & Rose, Coloradoa Boissev. & C.Davidson, Glandulicactus Backeb., Toumeya Britton & Rose

Stenocactus (K.Schum.) A.W.Hill

synonyms: Echinofossulocactus Britton & Rose, Efossus Orcutt (orth. var.)

Strombocactus Britton & Rose

Thelocactus (K.Schum.) Britton & Rose

synonyms: Hamatocactus Britton & Rose, Thelomastus Fric (nom. inval.)

Turbinicarpus (Backeb.) Buxb. & Backeb. – top cactus

synonyms: Gymnocactus Backeb., Normanbokea Kladiwa & Buxb., Rapicactus Buxb. & Oehme

Tribe Calymmantheae

Calymmanthium F.Ritter

synonyms: Diploperianthium F.Ritter (nom. inval.)

Tribe Cereeae

Arrojadoa Britton & Rose

synonyms: Pierrebraunia Esteves

Brasilicereus Backeb.

Cereus Mill. – sweet potato cactus

synonyms: Mirabella F.Ritter, Piptanthocereus (A.Berger) Riccob., Subpilocereus Backeb.

Cipocereus F.Ritter

synonyms: Floribunda F.Ritter

Coleocephalocereus Backeb.

synonyms: Buiningia Buxb.

Melocactus Link & Otto

synonyms: Cactus Britton & Rose

Micranthocereus Backeb.

synonyms: Austrocephalocereus Backeb., Siccobaccatus P.J.Braun & Esteves

Pilosocereus Byles & G. D. Rowley – tree cactus

synonyms: Pilocereus K.Schum., Pseudopilocereus Buxb.

Praecereus Buxb.

Stephanocereus A.Berger

Uebelmannia Buining

Tribe Hylocereeae

Disocactus Lindl.

synonyms: Aporocactus Lem., Aporocereus Fric & Kreuz. (orth. var.), Bonifazia Standl. & Steyerm., Chiapasia Britton & Rose, Disisocactus Kunze (orth. var.), Disocereus Fric & Kreuz. (orth. var.), Heliocereus (A.Berger) Britton & Rose, Lobeira Alexander, Mediocereus Fric & Kreuz. (orth. var.), Nopalxochia Britton & Rose, Pseudonopalxochia Backeb., Trochilocactus Linding., Wittia K.Schum., Wittiocactus Rauschert

Epiphyllum Haw. – climbing cactus

synonyms: Phyllocactus Link, Phyllocereus Miq.

Hylocereus (A.Berger) Britton & Rose – nightblooming cactus

synonyms: Wilmattea Britton & Rose

Pseudorhipsalis Britton & Rose

Selenicereus (A.Berger) Britton & Rose – moonlight cactus, nightblooming cereus

synonyms: Cryptocereus Alexander, Deamia Britton & Rose, Marniera Backeb., Mediocactus Britton & Rose, Strophocactus Britton & Rose, Strophocereus Fric & Kreuz. (orth. var.)

Weberocereus Britton & Rose

synonyms: Eccremocactus Britton & Rose, Eccremocereus Fric & Kreuz. (orth. var.), Werckleocereus Britton & Rose

Tribe Notocacteae

Austrocactus Britton & Rose

Blossfeldia Werderm.

Cintia Knize & Ríha

Copiapoa Britton & Rose

synonyms: Pilocopiapoa F.Ritter

Eriosyce Phil.

synonyms: Ceratistes Labour. (nom. inval.), Chileniopsis Backeb., Chileocactus Fric (nom. inval.), Chileorebutia Fric (nom. inval.), Chiliorebutia Fric (orth. var.), Delaetia Backeb., Dracocactus Y.Itô (nom. inval.), Euporteria Kreuz. & Buining, Hildmannia Kreuz. & Buining, Horridocactus Backeb., Islaya Backeb., Neochilenia Backeb. ex Dölz, Neoporteria Britton & Rose, Neoporteria Backeb., Neotanahashia Y.Itô, Nichelia Bullock (nom. inval.), Pyrrhocactus (A.Berger) A.W.Hill, Rodentiophila F.Ritter ex Backeb., Thelocephala Y.Itô

Eulychnia Phil.

synonyms: Philippicereus Backeb.

Frailea Britton & Rose

Neowerdermannia Fric

Parodia Speg.

synonyms: Acanthocephala Backeb., Brasilicactus Backeb., Brasiliparodia F.Ritter, Brasilocactus Fric (nom. inval.), Chrysocactus Y.Itô (nom. inval.), Dactylanthocactus Y.Itô, Eriocactus Backeb., Eriocephala Backeb., Friesia Fric (nom. inval.), Hickenia Britton & Rose, Malacocarpus Salm-Dyck, Microspermia Fric, Neohickenia Fric, Notocactus (K.Schum.) Fric, Sericocactus Y.Itô, Wigginsia D.M.Porter

Yavia R.Kiesling & Piltz

Tribe Pachycereeae

Acanthocereus (Engelm. ex A.Berger) Britton & Rose – triangle cactus

synonyms: Dendrocereus Britton & Rose, Monvillea Britton & Rose

Bergerocactus Britton & Rose – snake cactus

synonyms: Bergerocereus Fric & Kreuz. (orth. var.)

Carnegiea Britton & Rose – saguaro

Cephalocereus Pfeiff. – old man cactus

synonyms: Haseltonia Backeb., Neodawsonia Backeb., Pilocereus Lem.

Corryocactus Britton & Rose

synonym: Corryocereus Fric & Kreuz. (orth. var.), Erdisia Britton & Rose, Eulychnocactus Backeb. (nom. inval.)

Dendrocereus Britton & Rose – see Acanthocereus

Echinocereus Engelm. – hedgehog cactus

synonyms: Morangaya G.D.Rowley, Wilcoxia Britton & Rose

Escontria Rose

Isolatocereus Backeb. – see Stenocereus

Leptocereus (A.Berger) Britton & Rose

synonyms: Neoabbottia Britton & Rose

×Myrtgerocactus Moran

[= Myrtillocactus × Bergerocactus]

Myrtillocactus Console

synonyms: Myrtillocereus Fric & Kreuz. (orth. var.)

Neobuxbaumia Backeb.

synonyms: Pseudomitrocereus Bravo & Buxb., Rooksbya Backeb.

×Pacherocactus G.D.Rowley

[= Pachycereus × Bergerocactus]

Pachycereus (A.Berger) Britton & Rose

synonyms: Backebergia Bravo, Lemaireocereus Britton & Rose, Lophocereus (A.Berger) Britton & Rose, Marginatocereus (Backeb.) Backeb., Mitrocereus (Backeb.) Backeb., Pterocereus T.MacDoug. & Miranda

Peniocereus (A.Berger) Britton & Rose

synonyms: Cullmannia Distefano, Neoevansia W.T.Marshall, Nyctocereus (A.Berger) Britton & Rose

Polaskia Backeb.

synonyms: Chichipia Backeb. (nom. inval.), Heliabravoa Backeb.

Pseudoacanthocereus F.Ritter

Stenocereus (A.Berger) Riccob.

synonyms: Hertrichocereus Backeb., Isolatocereus Backeb., Isolatocereus (Backeb.) Backeb., Machaerocereus Britton & Rose, Marshallocereus Backeb., Neolemaireocereus Backeb., Rathbunia Britton & Rose, Ritterocereus Backeb.

Tribe Rhipsalideae

Hatiora Britton & Rose

synonyms: Epiphyllopsis Backeb. & F.M.Knuth, Hariota DC., Pseudozygocactus Backeb., Rhipsalidopsis Britton & Rose

Lepismium Pfeiff.

synonyms: Acanthorhipsalis (K.Schum.) Britton & Rose, Acanthorhipsalis Kimnach, Pfeiffera Salm-Dyck

Rhipsalis Gaertn.

synonyms: Cassytha Mill., Erythrorhipsalis A.Berger, Hariota Adans., Lymanbensonia Kimnach

Schlumbergera Lem. – Christmas cactus, Easter cactus

synonyms: Epiphyllanthus A.Berger, Epiphyllum Pfeiff., Opuntiopsis Knebel (nom. inval.), Zygocactus K.Schum., Zygocereus Fric & Kreuz. (orth. var.)

Tribe Trichocereeae

Acanthocalycium Backeb.

synonyms: Spinicalycium Fric (nom. inval.)

Arthrocereus A.Berger

Brachycereus Britton & Rose

Cleistocactus Lem.

synonyms: Akersia Buining, Bolivicereus Cárdenas, Borzicactella H.Johnson ex F.Ritter, Borzicactus Riccob, Borzicereus Fric & Kreuz. (orth. var.), Cephalocleistocactus F.Ritter, Cleistocereus Fric & Kreuz. (orth. var.), Clistanthocereus Backeb., Demnosa Fric, Gymnanthocereus Backeb., Hildewintera F.Ritter, Loxanthocereus Backeb., Maritimocereus Akers, Pseudoechinocereus Buining (nom. inval.), Seticereus Backeb., Seticleistocactus Backeb., Winteria F.Ritter, Winterocereus Backeb.

Cephalocleistocactus F.Ritter – see Cleistocactus

Denmoza Britton & Rose

Discocactus Pfeiff.

Echinopsis Zucc. – San Pedro cactus

synonyms: Acantholobivia Backeb., Acanthopetalus Y.Itô, Andenea Fric (nom. inval.), Aureilobivia Fric, nom. inval., Chamaecereus Britton & Rose, Chamaelobivia Y. Itô (nom. inval.), Cinnabarinea Fric ex F.Ritter, Echinolobivia Y.Itô (nom. inval.), Echinonyctanthus Lem., Furiolobivia Y.Itô (nom. inval.), Helianthocereus Backeb, Heterolobivia Y.Itô (nom. inval.), Hymenorebulobivia Fric (nom. inval.), Hymenorebutia Fric ex Buining, Leucostele Backeb., Lobirebutia Fric (nom. inval.), Lobivia Britton & Rose, Lobiviopsis Fric (nom. inval.), Megalobivia Y.Itô (nom. inval.), Mesechinopsis Y.Itô, Neolobivia Y.Itô, Pilopsis Y.Itô (nom. inval.), Pseudolobivia (Backeb.) Backeb., Rebulobivia Fric (nom. inval.), Salpingolobivia Y.Itô, Scoparebutia Fric & Kreuz. ex Buining, Setiechinopsis (Backeb.) de Haas, Soehrensia Backeb., Trichocereus (A.Berger) Riccob.

Espostoa Britton & Rose

synonyms: Binghamia Britton & Rose, Pseudoespostoa Backeb., Thrixanthocereus Backeb., Vatricania Backeb.

Espostoopsis Buxb.

synonyms: Gerocephalus F.Ritter

Facheiroa Britton & Rose

synonyms: Zehntnerella Britton & Rose

Gymnocalycium Pfeiff. ex Mittler – chin cactus

synonyms: Brachycalycium Backeb.

Haageocereus Backeb.

synonyms: Floresia Krainz & F.Ritter ex Backeb. (nom. inval.), Haageocactus Backeb. (nom. inval.), Lasiocereus F.Ritter, Neobinghamia Backeb., Peruvocereus Akers

×Haagespostoa G.D.Rowley

[= Haageocereus × Espostoa]

Harrisia Britton – apple cactus

synonyms: Eriocereus (A.Berger) Riccob., Roseocereus Backeb.

Lasiocereus F.Ritter – see Haageocereus

Leocereus Britton & Rose

Matucana Britton & Rose

synonyms: Eomatucana F.Ritter

Mila Britton & Rose

Oreocereus (A.Berger) Riccob.

synonyms: Arequipa Britton & Rose, Arequipiopsis Kreuz. & Buining, Morawetzia Backeb., Submatucana Backeb.

Oroya Britton & Rose

Pygmaeocereus H.Johnson & Backeb.

Rauhocereus Backeb.

Rebutia K.Schum.

synonyms: Aylostera Speg., Bridgesia Backeb., Cylindrorebutia Fric & Kreuz., Digitorebutia Fric & Kreuz., Echinorebutia Fric (nom. inval.), Eurebutia Fric (nom. inval.), Gymnantha Y.Itô, Mediolobivia Backeb., Mediorebutia Fric (nom. inval.), Neogymnantha Y.Itô, Reicheocactus Backeb., Setirebutia Fric & Kreuz. (nom. inval.), Spegazzinia Backeb., Sulcorebutia Backeb., Weingartia Werderm.

Samaipaticereus Cárdenas

Weberbauerocereus Backeb.

synonyms: Meyenia Backeb.

Yungasocereus F.Ritter