Azorella selago
Encyclopedia
Azorella selago is a species of cushion plant
native to the sub-Antarctic
islands of the Southern Ocean
, including the Crozet Islands
, the Possession Islands
, the Heard Island and McDonald Islands
, the Kerguelen Islands
, and the Prince Edward Islands
. The closely related Azorella macquariensis
, which is endemic to Macquarie Island
, was split
from it taxonomically
in 1989. A. selago is often a keystone species
where it occurs and is well studied for its contribution to its native ecosystems.
Cushion plant
A cushion plant is a compact, low growing, mat forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world...
native to the sub-Antarctic
Subantarctic
The Subantarctic is a region in the southern hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° – 60° south of the Equator. The subantarctic region includes many islands in the southern parts of the Indian Ocean, Atlantic Ocean and...
islands of the Southern Ocean
Southern Ocean
The Southern Ocean comprises the southernmost waters of the World Ocean, generally taken to be south of 60°S latitude and encircling Antarctica. It is usually regarded as the fourth-largest of the five principal oceanic divisions...
, including the Crozet Islands
Crozet Islands
The Crozet Islands are a sub-antarctic archipelago of small islands in the southern Indian Ocean. They form one of the five administrative districts of the French Southern and Antarctic Lands.-Geography:...
, the Possession Islands
Possession Islands
The Possession Islands are a group of small islands and rocks extending over an area of about , lying in the western part of the Ross Sea, southeast of Cape McCormick, Victoria Land...
, the Heard Island and McDonald Islands
Heard Island and McDonald Islands
The Heard Island and McDonald Islands are an Australian external territory and volcanic group of barren Antarctic islands, about two-thirds of the way from Madagascar to Antarctica. The group's overall size is in area and it has of coastline...
, the Kerguelen Islands
Kerguelen Islands
The Kerguelen Islands , also known as the Desolation Islands, are a group of islands in the southern Indian Ocean constituting the emerged part of the otherwise submerged Kerguelen Plateau. The islands, along with Adélie Land, the Crozet Islands and the Amsterdam and Saint Paul Islands are part of...
, and the Prince Edward Islands
Prince Edward Islands
The Prince Edward Islands are two small islands in the sub-antarctic Indian Ocean that are part of South Africa. The islands, named Marion Island and Prince Edward Island, are located at ....
. The closely related Azorella macquariensis
Azorella macquariensis
Azorella macquariensis, also known as Macquarie Azorella or Macquarie Cushions, is a species of cushion plant endemic to Australia’s subantarctic Macquarie Island. It was referred to the more widely distributed A. selago until 1989, when it was described as a separate species.-Description:Azorella...
, which is endemic to Macquarie Island
Macquarie Island
Macquarie Island lies in the southwest corner of the Pacific Ocean, about half-way between New Zealand and Antarctica, at 54°30S, 158°57E. Politically, it has formed part of the Australian state of Tasmania since 1900 and became a Tasmanian State Reserve in 1978. In 1997 it became a world heritage...
, was split
Lumpers and splitters
Lumping and splitting refers to a well-known problem in any discipline which has to place individual examples into rigorously defined categories. The lumper/splitter problem occurs when there is the need to create classifications and assign examples to them, for example schools of literature,...
from it taxonomically
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
in 1989. A. selago is often a keystone species
Keystone species
A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. Such species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and...
where it occurs and is well studied for its contribution to its native ecosystems.