Silphium 

Silphium is an unidentified plant that was used in classical antiquity as a ing, perfume, aphrodisiac, and medicine. It also was used as a contraceptive by ancient Greeks and Romans. It was the essential item of trade from the ancient North African city of Cyrene, and was so critical to the Cyrenian economy that most of their coins bore a picture of the plant. The valuable product was the plant's resin.