Zireh is what some parts of the world call black cumin, Nigella sativa. Its dark brown, crescent-shaped seeds serve as a spice and yield essential oils dominated by monoterpene aldehydes and terpene hydrocarbons — cuminaldehyde and gamma-terpinene among them. The seeds lend a warm, peppery, faintly bitter note to breads, curries, pickles, and traditional confectionery across the Middle East and South Asia, and the distilled oils are prized in flavouring and traditional preparations. Spice traders judge it on aroma intensity, seed plumpness, and freedom from adulteration with cheaper seeds. It should not be confused with true cumin or with the bunium species also called black cumin in some regions.