Tetradiclidaceae
Peganum harmala
Syrian rue · Harmal · Esfand
- Part used
- seed
- Native range
- Arid regions from the eastern Mediterranean through Central Asia to India; invasive in the western United States and parts of Australia
- Morphology
- A bushy perennial to about eighty centimetres of dry ground, with finely divided leaves and white flowers, followed by capsules of small angular brown seeds. Not related to true rue despite the name.
What is in it
Evidence
No supported medicinal use. Its alkaloids are of research interest as monoamine oxidase inhibitors.
Safety
A potent monoamine oxidase inhibitor, with all the interaction hazards that implies — the same pharmacology as the ayahuasca vine, in a plant sold cheaply as incense. Overdose causes vomiting, hallucination, bradycardia, tremor and, at higher doses, respiratory depression; poisonings are reported regularly in Iran and Morocco, including deaths, often after use as an abortifacient or a home remedy.
Interactions: Potentially fatal with SSRIs, SNRIs and other serotonergic drugs; Dangerous with tyramine-containing foods; Interacts through MAO inhibition with a wide range of medicines
Regulatory: Harmine and harmaline are controlled substances in Australia. The seed is widely sold as incense in its range.
Historical use
Burned as an incense against the evil eye across Iran, Turkey, Central Asia and northern India, a practice called esfand that remains entirely ordinary. Some scholars have proposed it as a candidate for the Vedic soma, which is one of several unresolved identifications.
Recorded as history and attributed where possible. Long use establishes that a plant was widely used, not that it worked, and not that it was safe.
Worth knowing
Its family placement is the most unsettled in this collection, and the disagreement is three-cornered. Older references put Peganum in Zygophyllaceae with the caltrops. APG IV moves it to Nitrariaceae, which is what most recent sources say. GBIF and Kew currently place it in Tetradiclidaceae. This entry follows its stated authority, as it does for elder and Rehmannia — but a reader checking any other reference should expect a different answer, and the plant has not moved.
Syrian rue is the same pharmacology as the ayahuasca vine, growing as a weed across the dry Old World and sold in markets for a few coins as incense.
That is a genuine and under-appreciated hazard. The beta-carbolines are monoamine oxidase inhibitors, and MAO inhibition is one of the most interaction-prone pharmacologies there is — dangerous with common antidepressants and with ordinary aged foods. A plant burned for protection against the evil eye in a thousand households is the same chemistry that ayahuasca tourism warnings are written about.
Poisonings are reported regularly across its range, most often after use as a home remedy or an abortifacient, and the seeds are not sold with any warning at all.
Nomenclature verified against GBIF backbone taxonomy.