''Opuntia galapageia'' is a species of

cactus A cactus (: cacti, cactuses, or less commonly, cactus) is a member of the plant family Cactaceae (), a family of the order Caryophyllales comprising about 127 genera with some 1,750 known species. The word ''cactus'' derives, through Latin, ...

. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the

Galápagos Islands The Galápagos Islands () are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of sli ...

, part of

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

. Forms occurring on different islands have been treated as separate species and subtaxa of these species. ''Opuntia echios'', ''Opuntia helleri'', ''Opuntia insularis'', ''Opuntia megasperma'', ''Opuntia myriacantha'' and ''Opuntia saxicola'' are now sunk within ''O. galapageia''.

Description

The variety ''Opuntia galapageia'' var. ''myriacantha'', synonym ''Opuntia galapageia'' var. ''echios'', has one of the longest spine lengths: up to in length, exceeded only by '' Ferocactus emoryi'' ssp. ''rectispinus'' at .

Taxonomy

''Opuntia galapageia'' was first described by

John Stevens Henslow John Stevens Henslow (6 February 1796 – 16 May 1861) was an English Anglican priest, botanist and geologist. He is best remembered as friend and mentor to Charles Darwin. Early life Henslow was born at Rochester, Kent, the son of a solicit ...

in 1837. It was first recorded by

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English Natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

on Santiago (James) Island. Darwin was ashore there for nine days in 1835. Subsequently, at least five other species of ''Opuntia'' were described from the Galápagos: ''Opuntia helleri'', ''Opuntia insularis'', ''Opuntia megasperma'', ''Opuntia myriacantha'' and ''Opuntia saxicola''. All were treated by David Hunt in 2006 as included within ''O. galapageia'', a placement accepted by the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

as of 2017, although they had been assessed as separate species in 2000.

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

also accepts the placement within ''O. galapageia'', and includes ''Opuntia echios'', in most cases placing the species in an infraspecific taxon (see the list below).

Infraspecific taxa

A large number of varieties and other infraspecific taxa have been named. ,

accepts the following: Two other infraspecific taxa that have been named are not recognized by Plants of the World Online as distinct from the species: *''Opuntia galapageia'' var. ''brossettii'' Backeb. *''Opuntia galapageia'' subvar. ''orientalis'' (J.T.Howell) Backeb.

Distribution

''Opuntia galapageia'' is

to the

. Forms occurring on different islands have been described as subtaxa of the species (see the list above). Island distributions given by Plants of the World Online include: * Fernandina **''O. galapageia'' var. ''insularis'' * Isabela **''O. galapageia'' subvar. ''inermis'' **''O. galapageia'' var. ''insularis'' **''O. galapageia'' var. ''profusa'' **''O. galapageia'' var. ''saxicola'' *

Seymour Seymour may refer to: Places Australia *Seymour, Victoria, a township ** Seymour railway station * Electoral district of Seymour, a former electoral district in Victoria * Rural City of Seymour, a former local government area in Victoria * Se ...

**''O. galapageia'' var. ''zacana'' * Pinzon **''O. galapageia'' var. ''macrocarpa'' * Santa Cruz **''O. galapageia'' var. ''gigantea'' * Santa Fe **''O. galapageia'' subvar. ''barringtonensis'' *

Santiago Santiago (, ; ), also known as Santiago de Chile (), is the capital and largest city of Chile and one of the largest cities in the Americas. It is located in the country's central valley and is the center of the Santiago Metropolitan Regi ...

**''O. galapageia'' var. ''profusa''

References

galapageia Cacti of South America Taxonomy articles created by Polbot Endemic flora of the Galápagos Islands {{Cactus-stub