Tetradrachm

Kyrene's silver coinage from this period derives its entire economic rationale from silphium, the now-extinct plant the city harvested and exported across the Mediterranean world. The plant was so central to Kyrenaean wealth that it functioned almost as a monetary backing — Rome eventually stored it in the treasury alongside gold and silver reserves. By the first century AD it was gone entirely, likely due to overgrazing and unsustainable harvest, making these early coins artifacts of a trade commodity that no civilization has since been able to replicate or even botanically identify with certainty.