Sarso Kali (Black Mustard, Rhamphospermum nigrum, formerly Brassica nigra) is an annual plant native to cooler regions of North Africa, temperate Europe, and parts of Asia, including India. The plant is cultivated for its dark-brown-to-black seeds, which are commonly used as a spice in cooking and as an ingredient in various cuisines. Black mustard seeds contain plant-based compounds such as sinigrin, which contributes to their characteristic pungent flavor. In Indian culture, mustard seeds are also valued for their use in rituals and as a traditional spice.