Atriplex are C-plants, with a characteristic leaf anatomy (kranz anatomy). The genus "Atriplex" is distributed nearly worldwide from subtropical to temperate and to subarctic regions. Most species-rich are Australia, North America, South America and Eurasia. Many species are halophytes and are adapted to dry environments with salty soils. The genus evolved in Middle Miocene, the C-photosynthesis pathway developed about 14.1-10.9 million years ago, when the climate became increasingly dry. The genus diversified rapidly and spread over the continents. The C"Atriplex" colonized North America probably from Eurasia during the Middle/Late Miocene, about 9.8-8.8 million years ago, and later spread to South America.
Tasmanian cushion plants population size (Threatened Species Section, 2012). The cause of the dieback is unknown and under investigation. Once dead, the cushions may erode and as a result could have adverse impacts on the rest of feldmark vegetation due to its vital structural role in the ecosystem. Potential factors that threaten "Azorella macquariensis" include: "Colobanthus pulvinatus" is listed as rare under the Threatened Species Protection Act 1995. Tasmanian cushion plants Tasmanian cushion plants are low growing, highly compact, woody, spreading mats that can grow up to 3 m in diameter, located mainly on the island of Tasmania. These mats are made up