"It is considered to be closer to wild cabbage than most domesticated forms. The species *Brassica oleracea* contains a wide array of vegetables including broccoli, cauliflower, collard greens, and brussels sprouts. The cultivar group Acephala also includes spring greens and collard greens, which are extremely similar genetically." - Wikipedia

Kale or borecole is a form of cabbage (*Brassica oleracea* Acephala Group), green or purple, in which the central leaves do not form a head.