Black mustard seeds are those tiny little strong flavored seeds used most commonly in Indian cooking. They have dark brown with a slightly reddish hue as compared to some seeds. They are the most pungent of all mustard seeds. They belong to the Brassica family & are scientifically known as Brassica Juncea. Brown mustard, which is actually dark in color, has a pungent acrid taste. Mustard seeds are an excellent source of selenium and a very good source of omega-3 fatty acids and manganese. These seeds are mainly used as a spice and to flavor mustard condiment.