Brassica oleracea, (family Brassicaceae), also referred to as cole crops (Nieuwhof 1969; Yamaguchi 1983; Nonnecke 1989), is an economically important vegetable species composed mostly of biennially herbaceous plants, grown as annuals or biennials, depending on the part harvested. Practically every part of the plant can be used, including leaves (cabbage, kale), axillary buds (Brussels sprouts), stems (kohlrabi), flower buds (broccoli), and floral primordia (cauliflower). It is a highly polymorphic species, and has over 40 members (Bailey 1976). Table 1 summarizes eight of the most important varieties commonly grown throughout the world.