Brussels sprouts are thought to be native to Belgium, specifically a region near its capital, Brussels, after which they are named. They remained a local crop in this area until their use spread across Europe during World War I. Brussels sprouts are now cultivated throughout Europe and have been naturalized in the United States. They are a cold hardy food plant that thrives in winter months in temperate climates with adequate to supple supplies of rainfall and irrigation.Brussels sprouts, botanical name Brassica oleracea, belong to the Brassicaceae family. They are the axillary buds of the plant, which grow progressively from an upward sprouting, stem. The Brassicaceae is an economically important food plant family known as the mustard plants, crucifers and cabbages. Modern cultivars of Brussels sprouts have been developed to remove the bitterness that they have been historically associated with. Five common types of Brussels sprouts include Rampart, Content, Oliver, Rowena and Valiant. Each variety has its own time preference of cultivation.