Dill is an annual herb in the celery family Apiaceae. Dill grows into slender hollow stems and alternate, finely divided, softly delicate leaves. Similar leaves to fennel, its flowers are white to yellow, in small umbels.
Fresh and dried dill leaves (sometimes called "dill weed" to distinguish it from dill seed) are widely used as herbs in Europe and central Asia. Like caraway, the fernlike leaves of dill are aromatic and are used to flavor many foods such as gravlax (cured salmon) and other fish dishes, borscht and other soups, as well as pickles (where the dill flower is sometimes used). Dill is best when used fresh as it loses its flavor rapidly if dried; however, freeze-dried dill leaves retain their flavor relatively well for a few months.