Black Mustard seeds are the small round seeds of various mustard plants. The seeds are usually about 1 or 2 mm in diameter. Mustard seeds may be colored from yellowish white to black. They are important spices in many regional foods. Black Mustard Seed (Brassica Nigra) is an annual weedy plant cultivated for its seeds, which are commonly used as a spice.   We are one of the most active mustard seed suppliers. Our Black Mustard Seeds are a selection of best seeds.