Coriander seed has been used in cooking dating back thousands of years. Coriander has even been found in Canopic jars in some ancient Egyptian burial chambers. Coriander is the name of the seed of a cilantro plant ? once the herb begins producing seeds, the leaves become bitter and inedible, but the seeds can be ground or used whole for a warm spicy flavor with a slight hint of citrus. Whole coriander seeds can be added to sauces, soups, and stews, used in pickling spice blends, crushed and sprinkled on greens, or added to seafood boil.