In the medieval ages, fennel was hung or placed over doorways because it was believed to protect against evil spirits. In addition, the seeds were also put into keyholes, for it was said to prevent ghosts from entering houses in the middle of the night. (fennel)
In another article, Roman warriors have eaten fennel seeds because they believed that it would make them stronger. Another interesting folklore is that fennel was said to have been ingested by snakes when they shed their skin to sharpen their vision.
According to mdidea.com, its name, “fennel” came from the battle at Marathon where the Greeks fought the Persians and it so happened to be on a fennel field. Some Greek story states that a stalk of fennel was said to have held a smoldering coal, which was supposed to contain “knowledge from Mount Olympus”(drugs.com). Greek myths and folklore also claim that the plant fennel was linked to the god of wine and feast, Dionysus. (Benefiits of Fennel