Amaranth, shown here in a Penn State greenhouse, is an annual tropical edible plant that is sometimes cultivated as a leafy vegetable. It is one of the species mentioned in the study, “Food Resilience in a Dark Catastrophe,” authored by Daniel Winstead and Michael Jacobson in the College of Agricultural Sciences.
https://www.psu.edu/news/research/story/how-would-nuclear-winter-impact-food-production