Black mustard is the smallest of the mustard seeds and is oblong in shape. Black mustard seeds have a well deserved reputation for their pungent spicy aroma and flavor. Most common in Indian cooking black mustard seeds are often fried in oil, making them sweet and mild while releasing a nutty aroma.
Mustard seeds are the small round seeds of various mustard plants. They are an important spice in many regional foods and may come from one of three different plants: black mustard (Brassica nigra), brown Indian mustard (B. juncea), or white/yellow mustard (B. hirta/Sinapis alba).