Plants that produce mustard seeds are various and belong to different species. This means that the term "mustard" represents a lexical simplification that totally disregards the botanical nature of this plant. They are herbaceous plants belonging to the family of the brassicaceae, genus Brassica. The seeds are quite different in shape and colour as well as in organoleptic characteristics. For example, black mustard, or B. nigra, is a very large plant tht produces small black berries with a strong taste. The first traces documenting its use where found in the area surrounding Egypt, in which it seems to be native. B. alba is instead of modest dimensions but produces big, yellow and little spicy seeds. It is typical of the Mediterranean basin and today is widely diffused also in the American continent. It is called white mustard in Europe or yellow mustard in the U.S.