Opuntia echios is a species of plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

 in the Cactaceae family. It is endemic to the Galápagos Islands

Galápagos Islands

The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...

 (Ecuador

Ecuador

Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

) and is commonly known as the Galápagos prickly pear, but there are five other species of prickly pears

Opuntia

Opuntia, also known as nopales or paddle cactus , is a genus in the cactus family, Cactaceae.Currently, only prickly pears are included in this genus of about 200 species distributed throughout most of the Americas. Chollas are now separated into the genus Cylindropuntia, which some still consider...

 that also are endemic to the archipelago (O. galapageia

Opuntia galapageia

Opuntia galapageia is a species of plant in the Cactaceae family. It is endemic to the Galapagos Islands . There are three varieties: Opuntia galapageia var. galapageia on Bartolome, Santiago and Pinta, Opuntia galapageia var. macrocarpa on Pinzon and Opuntia galapageia var. profusa on...

, O. helleri

Opuntia helleri

Opuntia helleri is a species of plant in the Cactaceae family. This vulnerable species is endemic to the Galapagos Islands , where restricted to Wolf, Darwin, Marchena and Genovesa.-Source:* Tye, A. 2000. . Downloaded on 22 August 2007....

, O. insularis

Opuntia insularis

Opuntia insularis is a species of plant in the Cactaceae family. This endangered species is endemic to the Galapagos Islands , where restricted to Fernandina and Isabela.-Source:* Tye, A. 2000. . Downloaded on 22 August 2007....

, O. megasperma

Opuntia megasperma

Opuntia megasperma is a species of plant in the Cactaceae family. This vulnerable species is endemic to the Galapagos Islands , where restricted to Floreana, San Cristobal and Espanola.-Source:...

and O. saxicola

Opuntia saxicola

Opuntia saxicola is a species of plant in the Cactaceae family. This critically endangered species is endemic to the Galapagos Islands , where restricted to Isabela.-Source:* Tye, A. 2000. . Downloaded on 22 August 2007....

).
There are five varieties of Opuntia echios, each with a different appearance and distribution: Opuntia echios var. echios on the islands of Santa Cruz

Santa Cruz Island (Galápagos)

Santa Cruz Island is one of the Galápagos Islands with an area of and a maximum altitude of .Situated in the center of the archipelago, Santa Cruz is the second largest island after Isabela. Its capital is Puerto Ayora, the most populated urban centre in the islands. On Santa Cruz there are some...

, Baltra

Baltra Island

Baltra Island, or Isla Baltra, is a small island of the Galápagos Islands. Also known as South Seymour , Baltra is a small flat island located near the center of the Galápagos. It was created by geological uplift...

, Daphne Major

Daphne Major

Daphne Major is a volcanic island just north of Santa Cruz Island and just west of the Baltra Airport in the archipelago Colon, commonly known as the Galápagos Islands...

 and South Plaza

South Plaza Island

South Plaza is a small island off the east coast of Santa Cruz in the Galapagos Islands. It has an area of 0.13 km˛ and a maximum altitude of 23 meters....

, Opuntia echios var. barringtonensis on Santa Fe

Santa Fe Island

Santa Fe Island , also called Barrington Island after admiral Samuel Barrington, is a small island of 24 km² which lies in the centre of the Galapagos archipelago, to the south east of Santa Cruz Island. Geologically it is one of the oldest, since volcanic rocks of about 4 million years old...

, Opuntia echios var. gigantea near Academy Bay

Academy Bay

Academy Bay is the natural harbor of Santa Cruz Island in the Galápagos Islands archipelago. The bay was named for the California Academy of Sciences, which sent an expedition here in 1905. It is home to the Charles Darwin Research Station, founded in 1959 to preserve and study the Galapagos...

 on Santa Cruz

Santa Cruz Island (Galápagos)

Santa Cruz Island is one of the Galápagos Islands with an area of and a maximum altitude of .Situated in the center of the archipelago, Santa Cruz is the second largest island after Isabela. Its capital is Puerto Ayora, the most populated urban centre in the islands. On Santa Cruz there are some...

, Opuntia echios var. inermis on the Sierra Negra Volcano

Sierra Negra (Galápagos)

Sierra Negra is a large shield volcano at the South eastern end of Isabela Island in the Galapagos that rises to an altitude of 1124m. It coalesces with the volcanoes Cerro Azul to the west and Alcedo to the north...

 on Isabela and Opuntia echios var. zacana on North Seymour

North Seymour Island

North Seymour is a small island near to Baltra Island in the Galapagos Islands. It was formed by uplift of a submarine lava formation. The whole island is covered with low, bushy vegetation....

.