Brassica is a genus of plants in the mustard family (Brassicaceae). The members of the genus may be collectively known either as cabbages, or as mustards.
This genus is remarkable for containing more important agricultural and horticultural crops than any other genus. It also includes a number of weeds, both wild taxa and escapees from cultivation. It includes over 30 wild species and hybrids, and numerous additional cultivars and hybrids of cultivated origin. Most are annuals or biennials, but some are small shrubs.
The genus is native in the wild in western Europe, the Mediterranean and temperate regions of Asia. In addition to the cultivated species, which are grown worldwide, many of the wild species grow as weeds, especially in North America, South America, and Australia.
Almost all parts of some species or other have been developed for food, including the root (swedes, turnips), stems (kohlrabi), leaves (cabbage, brussels sprouts), flowers (cauliflower, broccoli), and seeds (many, including mustard seed, oilseed rape). Some forms with white or purple foliage or flowerheads, are also sometimes grown for ornament.