wild parsnip: biennial weed in Europe and America having large pinnate leaves and yellow flowers and a bitter and somewhat poisonous root; the ancestor of cultivated parsnip
parsnip: a strong-scented plant cultivated for its edible root
chlorine: a common nonmetallic element belonging to the halogens; best known as a heavy yellow irritating toxic gas; used to purify water and as a bleaching agent and disinfectant; occurs naturally only as a salt (as in sea water)