celery, biennial plant (Apium graveolens) of the family Umbelliferae (parsley family), of wide distribution in the wild state throughout the north temperate Old World and much cultivated also in America. It was first cultivated as a medicinal, then (during the Middle Ages) as a flavoring, and finally as a food, chiefly for soups and salads. The seeds are still used for seasoning. Celeriac is a variety cultivated chiefly in N Europe for the large edible turniplike root. Celery is classified in the division Magnoliophyta, class Magnoliopsida, order Umbellales, family Umbelliferae.