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.
Salicornioideae surface may be smooth, papillose, reticulate, tuberculate or longitudinally ribbed. The embryo is curved, half-annular or horseshoe-shaped, rarely only slightly curved. In most genera, the seed contains copious perisperm, but a feeding tissue is missing in "Salicornia" and "Sarcocornia". The majority of the Salicornieae species are C-plants. There is only one species that has developed C-photosynthesis, "Tecticornia indica" (syn. "Halosarcia indica"). Plants from the Salicornioideae are found around the world. All are halophytes, growing in coastal or inland saline habitats. The Salicornioideae originated in Eurasia about 38-28 million years ago, during the Late Eocene/Early Oligocene, and radiated rapidly into its