Cauliflower is one of several vegetables cultivated from the species Brassica oleracea in the genus Brassica, which is in the Brassicaceae family.

Brassica is a genus of plants in the cabbage and mustard family (Brassicaceae). The members of the genus are informally known as cruciferous vegetables, cabbages, mustard plants, or simply brassicas. Crops from this genus are sometimes called cole crops—derived from the Latin caulis, denoting the stem or stalk of a plant.