Azorella macquariensis
Encyclopedia
Azorella macquariensis, also known as Macquarie Azorella or Macquarie Cushions, is a species of cushion plant
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...

 endemic to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

’s subantarctic
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...

 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...

. It was referred to the more widely distributed A. selago
Azorella selago
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,...

until 1989, when it was described as a separate species.

Description

Azorella macquariensis is a perennial cushion-forming herb. Individuals form cushions and mats that may vary in size from a few centimetres to several metres in diameter and up to 60 cm in height. It is a keystone species dominating Macquarie's feldmark
Feldmark
Feldmark, also spelt fjaeldmark , is a plant community characteristic of sites where plant growth is severely restricted by extremes of cold and by exposure to wind, typical of alpine tundra and subantarctic environments.-Description:...

 habitat, in which it is the only vascular plant
Vascular plant
Vascular plants are those plants that have lignified tissues for conducting water, minerals, and photosynthetic products through the plant. Vascular plants include the clubmosses, Equisetum, ferns, gymnosperms and angiosperms...

, forming a major structural component of the vegetation. The feldmark community covers about half the island in the most wind-exposed areas of the plateau some 200–400 m above sea level. The plant flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s from December to February and fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

s from January to April. It turns brown and ceases to grow during winter (from June to August).

Conservation status

Azorella macquariensis has suffered a catastrophic decline due to dieback from unknown causes, first noticed in December 2008, and is considered to be endangered.
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