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 are also often considered "nurse species", as their presence is necessary in order for many other alpine species to become established. Cushion plants have been found to enhance species richness in areas with inherent impoverished local diversity (Cavieres et al. 2014). This effect is due to their low and compact growth form that alleviates severe alpine conditions (Cavieres et al. 2014). Several Tasmanian cushion species have been found to have a surface temperature up to 10 °C greater than the ambient temperatures (Gibson, 1988). The warmer temperatures allow the plants to continue to photosynthesize and grow in conditions that would