parsnip, garden plant ( Pastinaca sativa ) of the family Umbelliferae (parsley family), native to the Old World. It has been cultivated since Roman times for its long, fleshy, edible root. Wine and beer have also been made from it. The wild form has become naturalized in North America, often proving a noxious weed. Parsnip is a biennial but is cultivated as an annual. The root can be left in the ground all winter without deterioration. It is also used as livestock feed. Parsnip is classified in the division Magnoliophyta, class Magnoliopsida, order Apiales, family Umbelliferae.