Silphium was the name of a plant that grew only on a strip of land about 125 by 35 miles along the North African coast, in the region of Cyrenaica — and for centuries it was one of the most coveted commodities in the ancient Mediterranean.
Julius Caesar once stored some 1,080 pounds of its resin in Rome’s treasury. By the first century A.D., the plant was thought to be extinct. Today it is recognized as the first documented case of species extinction in recorded history.
The Greek city of Cyrene, founded in what is now Libya, built much of its wealth on the silphium trade.
The plant was so central to the city’s economy that it appeared on most of the coins minted by Cyrene and Barca, another city-state in the region, between the sixth and fourth centuries B.C.
Food, Medicine, and Currency
Silphium served many purposes.
Its stalks were cooked and eaten as a vegetable, its roots were eaten raw with vinegar, and its resin — known in Latin as laser or laserpicium — was used as a seasoning throughout Greco-Roman cuisine, documented in Apicius’s cookbook.
It was also valued as fodder: animals that grazed on it were believed to yield tastier meat.
In medicine, the Greek physician Hippocrates recommended it for treating hernias, while other ancient sources linked it to the treatment of coughs, fevers, warts, and assorted aches and pains.
A further use, documented by multiple historians, was as a contraceptive and possible abortifacient — a reputation that fueled much of the demand for the plant, and much of its mystique, in antiquity.
Some researchers have also proposed that the heart-shaped seeds of silphium may be the origin of the modern heart symbol, though that idea has not won broad scholarly acceptance.
A Plant That Refused to Be Cultivated
The Greek botanist Theophrastus, a student of Aristotle, described silphium as a plant with a thick root covered in dark bark, a hollow stem resembling fennel, and golden leaves similar to those of celery.
He also noted a characteristic that would prove decisive: silphium did not thrive in cultivated soil and would not grow outside its natural habitat in the southern steppes of Cyrenaica.
That combination — an extraordinarily limited growing range and the impossibility of cultivating it elsewhere — left the plant entirely dependent on wild populations.
Any additional pressure on those populations, whether from harvesting or grazing, could not be offset by new plantings.
The Theories Behind Its Disappearance
The traditional explanation, held for centuries, points to overharvesting.
Growing demand across the Mediterranean basin led to more intensive collection than the plant could sustain, compounded by the grazing of goats and sheep across its territory.
Pliny the Elder, who wrote about silphium when it had already become scarce, placed part of the blame on tax collectors for driving up its price.
A 2022 study published in the journal Frontiers in Conservation Science challenged that account, however, proposing that the main culprit was desertification in ancient Cyrenaica, which shrank the plant’s available habitat independently of direct human exploitation.
A more speculative hypothesis holds that silphium may have been a hybrid, which would explain why it was so difficult to propagate from seed and could only spread from its roots.
According to Pliny, the last stalk of silphium found in Cyrenaica was presented as a curiosity to Emperor Nero in the first century A.D.
The Search for a Modern Successor
With no preserved biological sample, the exact identity of silphium remains unresolved.
The most widely accepted hypothesis places it within the genus Ferula, commonly known as giant fennel, though it has also been linked to the genus Thapsia or to a finer variety of asafoetida — the spice that ultimately replaced it in Roman kitchens.
In 2021, researcher Mahmut Miski of Istanbul University published a study on a species of Ferula growing endemically near Mount Hasan in central Anatolia, more than 930 miles from Cyrenaica.
The plant, Ferula drudeana, shares several traits with the silphium depicted on ancient coins: its overall shape, its yellow foliage at maturity, its slow growth, and an aromatic resin with properties similar to those the classical authors described.
The study itself cautions, however, that this species belongs to a lineage originating in the Caspian Sea region, with no known geographic connection to the Libyan coast where the original silphium grew.
The irony is hard to miss.
Ferula drudeana, the most frequently cited candidate to be silphium’s modern successor, is today an endangered species — with very few known populations and under pressure from illegal harvesting for use as an aphrodisiac.
