Collard refers to certain loose-leafed cultivars of Brassica oleracea, the same species as many common vegetables, including cabbage (Capitata Group) and broccoli (Italica Group). Collard is a member of the Viridis Group of Brassica oleracea. American collard cultivars are more correctly placed in the Viridis cultivar group due to a high genetic similarity with cabbage, although older publications often include them within the Acephala Group (kale). The name "collard" comes from the word "colewort" (a medieval term for non-heading brassica crops).The plants are grown as a food crop for their large, dark-green, edible leaves, mainly in Brazil, Portugal, Zimbabwe, the southern United States, Tanzania, Kenya, Uganda, the Balkans, Italy, northern Spain, and India. Collard greens have been eaten for at least 2000 years, with evidence showing that the ancient Greeks cultivated several types of collard, as well as kale.