Silphium
Silphium (also known as laserwort or laser; Ancient Greek: σίλφιον, sílphion) is an unidentified plant that was used in classical antiquity as a seasoning, perfume, aphrodisiac, and medicine.
It was an 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 an image of the plant. The valuable product was the plant's resin, called in Latin laserpicium, lasarpicium, or laser (Laserpitium and Laser were used by botanists to name genera of aromatic plants, but the silphium plant is not believed to belong to these genera).
The exact identity of silphium is unclear. It was claimed to have become extinct in Roman times, but is commonly believed to have been a relative of giant fennel in the genus Ferula. The extant plant Thapsia gummifera has been suggested as another possibility. Another conjecture is that it was simply a high-quality variety of asafoetida, a common seasoning in the Roman Empire, for the two were considered the same by many Romans, including the geographer Strabo.
Silphium was considered invaluable by all who held it. The plant was sung about by Roman poets and singers, who considered it equivalent to its weight in gold. Historically, Pliny the Elder blamed silphium's valuation on "tax-farmers", and Julius Caesar directly registered silphium as "1500 pounds of laser" in the Roman treasury.