They would bathe a newborn baby's eyes in fennel water to improve its vision. There are two different kinds of fennel. Florence fennel is used as a vegetable. It has a stalk that can grow as big as bamboo and is delicious as a bed to roast or grill fish. It also has a round bulb at its base in the shape of an onion.
Supermarkets erroneously label it anise.
Growing fennel is incredibly easy. It will thrive anywhere especially in sandy poor soil with a lot of sun and should be kept on the dry side. Don't pamper fennel. Give it lots of room to grow and just leave it alone. It is easily propagated by seeds sown early in April, and will bloom in July and August.