Brassica nigra, or black mustard, is an annual plant cultivated for its dark-brown-to-black seeds, which are commonly used as a spice.Black mustard is the smallest of the mustard seeds and is oblong in shape. While mustard seeds are frequently used in preparing condiments, black mustard is rarely used in this manner due to its pungency being very volatile. Black mustard seeds have a well deserved reputation for their pungent spicy aroma and flavor.
