The Greeks and Romans used fennel for medicinal and culinary purposes. In the mid-16th century, herbalist John Gerard devoted a section of his "herbal" to the plant, whose seeds "taste sweet like unto Annise seeds."
A variety of Foeniculum vulgare, 'azoricum' or "Florence fennel" is most often grown for its flavorful stalks and swollen base, referred to as its "bulb." Fennel bulbs are used in preparing fish dishes as well as served raw in salads. The greens and seeds are used as flavor enhancers.
Like other members of the Umbelliferae family, fennel is a host plant for swallowtail butterflies, including anise swallowtails in the Western United States and black swallowtails in the East. Even if you never use fennel for cooking, the plant does well in butterfly and habitat gardens.