Also known as Mountain spinach, French spinach, Giant Lambsquarters, Orache Atriplex hortensis Chenopodiaceae Family
Heirloom with Western Asia and Mediterranean origin. Popular in Europe, particularly France. Although the flavor is a bit like spinach, it's not related. It was very popular until real spinach came along from Persia nearly a thousand years ago.
Depending on the variety, leaves can range from bright yellow to magenta to deep purple.