Brassicaceae is a family of plants including mustard, wasabi, and horseradish. They are also called the mustard family, or cabbage family. Some plants in this family are hot when you eat them, so they are used as spices. Another group includes the cabbages, where there are broccoli, cauliflower, and cabbage. Another name for this family is Cruciferae.
The flowers of this family have four petals and look like a cross. The name comes from the genus in it, Brassica.