Fennel (Foeniculum vulgare) is a flowering plantspecies in the carrot family. It is a hardy, perennialherb with yellow flowers and feathery leaves. It is indigenous to the shores of the Mediterranean but has become widely naturalized in many parts of the world, especially on dry soils near the sea-coast and on riverbanks. It is indigenous to the shores of the Mediterranean but has become widely naturalized in many parts of the world, especially on dry soils near the sea-coast and on riverbanks. Florence fennel or finocchio is a selection with a swollen, bulb-like stem base that is used as a vegetable. Fennel is used as a food plant by the larvae of some Lepidoptera species including the mouse moth and the anise swallowtail.