Form of cabbage (Brassica oleracea, Gongylodes group) of the mustard family, which originated in Europe. Its most distinctive feature is the greatly enlarged, globular to slightly flattened stem that grows just above the soil. Its flesh resembles that of a turnip but is sweeter and milder. Low in calories, kohlrabi is an excellent source of vitamin C, minerals, and dietary bulk. The young tender leaves may be eaten as greens; the thickened stem is served raw or cooked. Though not widely grown commercially, it is popular in some regions.