(Brassica oleracea, Acephala group), headless form of cabbage (q.v.) of the mustard family (Brassicaceae). It bears the same botanical name as kale, from which it differs only in leaf characters; collard leaves are much broader, are not frilled, and resemble the rosette leaves of head cabbage. The main stem reaches a height of 60–120 cm (24–48 inches) with a rosette of leaves at the top. Lower leaves commonly are harvested progressively; the entire young rosette is sometimes harvested. The plant is a source of nutritionally important minerals and of vitamins A and C. It is commonly raised as a source of winter greens in the southern United States, where it is customarily boiled with a seasoning of pork fat.