Cilantro is the herb, also called coriander, commonly used in Mexican salsa.
Cilantro refers primarily to the fresh leaves and tender stems of Coriandrum sativum. In the United States and many Spanish-speaking countries, “cilantro” distinguishes the leaves from the plant's dried seeds, which are usually called coriander. In British English, coriander can refer to both the leaves and seeds, so the names vary by region.
The herb is commonly chopped into salsa, guacamole, chutneys, salads, soups, and meat dishes. Its fresh flavor is often described as citrusy or green, but some people experience it as soapy. This difference is associated partly with genetic variation affecting sensitivity to certain aldehyde compounds in the leaves.
Coriander originated in the Mediterranean region and has been used for centuries in cuisines across Europe, Asia, and the Americas. A frequent mistake is treating cilantro and coriander seed as interchangeable: they come from the same plant but have noticeably different flavors and culinary uses.