Amaranth seedlings being grown in southern Mexico’’s Tehuacan valley. The plant’s seeds are high in protein and its leaves are high in iron, vitamin C, and calcium. Photo by Sam Eaton.

Amaranth virtually disappeared from Mexican diets after the Spanish banned it because of its use in human sacrifice rituals. Now there are efforts to bring it back for its superior nutritional qualities and its hardiness in the face of climate change.