It is a member of the family Apiaceae.
It is a hardy, perennial, umbelliferous herb, with yellow flowers and feathery leaves.
It is generally considered indigenous to the shores of the Mediterranean, but has become widely naturalised in many parts of the world, especially on dry soils near the sea-coast and on river-banks.
It is a highly aromatic and flavorful herb with culinary and medicinal uses, and is one of the primary ingredients of absinthe.
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.
Fennel is a perennial herb.
It is erect, glaucous green, and grows to heights of up to 2.5 m, with hollow stems.
The leaves grow up to 40 cm long, they are finely dissected, with the ultimate segments filiform, about 0.5 mm wide.
The flowers are produced in terminal compound umbels 5–15 cm wide, each umbel section having 20–50 tiny yellow flowers on short pedicels.
The fruit is a dry seed from 4–10 mm long, half as wide or less, and grooved.
Fennel contains anethole, which can explain some of its medical effects: it, or its polymers, act as phytoestrogens.
Syrup prepared from fennel juice was formerly given for chronic coughs.
Some people use fennel as a diuretic and it may be an effective diuretic and a potential drug for treatment of hypertension.
Many egg, fish, and other dishes employ fresh or dried fennel leaves.
Florence fennel is a key ingredient in some Italian and German salads, often tossed with chicory and avocado, or it can be braised and served as a warm side dish.
It may be blanched or marinated, or cooked in risotto.