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.
Insectivorous Plants (book) roots, but these plants have poor root systems and have adapted to receive nutrients (primarily nitrogenous substances) from captured insects. Darwin noted that "Drosera" and other carnivorous plants also feed on seeds, thus also making them vegetable feeders (p. 134). His notable observations are (p. 3–4): 1. The sensitivity of the glands to slight pressure and to minute doses of nitrogenous substances. He noted that although there is extreme sensitivity it is wholly appropriate to the purpose of gaining sustenance, e.g. they do not respond to heavy rain falling on them nor to the wind blowing other leaves against them.