Brassica refers to members of the Mustard genus, Brassicaceae. Sometimes called Cole Crops, these include smaller plants like radishes, kohlrabi, turnips, and arugula, as well as the larger group that includes broccoli, Brussels sprouts, cabbage, collards, and kale.
The genus Brassicaceae is remarkable because it includes the highest number of agricultural and food plants of all plant genera. Many of the varieties are well suited to colder climates.