fennel Foeniculum vulgare, a plant of the parsley family (Umbelliferae), with feathery leaves and yellow flowers. It has been used in Europe since the beginning of the classical era, and probably earlier, both as a source of seed for flavouring and as a vegetable, in which case the stalk is the part eaten. It is now grown in moderately warm regions worldwide, mainly for seed.
There are three principal sorts of fennel: bitter and sweet fennel, both used as herbs, and Florence fennel, which provides a vegetable in the form of the swollen base of its stem.
