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.
Halosere Halosere In ecology, a halosere is a succession in a saline environment. An example of a halosere is a salt marsh. In a river estuary, large amounts of silt are deposited by the ebbing tides and inflowing rivers. The earliest plant colonizers are algae and eel grass, which can tolerate submergence by the tide for most of the 12-hour cycle and which trap mud, causing it to accumulate. Two other colonizers are "Salicornia" and "Spartina", which are halophytes, i.e. plants that can tolerate saline conditions. They grow on the inter-tidal mudflats with a maximum of four hours' exposure to air