"B. oleracea" has become established as an important human food crop plant, used because of its large food reserves, which are stored over the winter in its leaves. It is rich in essential nutrients including vitamin C. It has been bred into a wide range of cultivars, including cabbage, broccoli, cauliflower, brussels sprouts, collards, and kale, some of which are hardly recognizable as being members of the same genus, let alone species. The historical genus of Crucifera, meaning "cross-bearing" in reference to the four-petaled flowers, may be the only unifying feature beyond taste.