Aristolochiaceae
Aristolochia clematitis
Birthwort · European birthwort
- Part used
- rootaerial
- Native range
- Southern and central Europe, naturalised further north; the genus is worldwide
- Morphology
- Perennial to about a metre, heart-shaped leaves, and dull yellow flowers with a bent tube that traps insects until the pollen is shed.
What is in it
Evidence
No supported therapeutic use. The genus is now studied as a toxin rather than as a medicine.
Safety
Aristolochic acid is classified by the IARC as a Group 1 human carcinogen, the same category as tobacco and asbestos, and there is no known safe dose. It causes irreversible progressive kidney failure and urothelial carcinoma, with a latency of years. Around a hundred cases arose from a Brussels weight-loss clinic from 1990 after a supplier substituted Aristolochia fangchi for Stephania tetrandra; many required dialysis or transplant. Balkan endemic nephropathy, known along the Danube since the 1950s, was eventually traced to A. clematitis seed contaminating wheat.
Regulatory: Banned or restricted in most jurisdictions including Australia, the EU, the UK and the US. Still found in imported preparations.
How the traditions classify it
Three systems, rating the same plant. Where they disagree, none of them is correcting the others — they are separate frameworks that arrived at their categories independently.
Historical use
Named and used in Greek medicine for childbirth and for snakebite, and retained in European herbals for two thousand years. Related species entered Chinese materia medica under names including guang fang ji and mu tong.
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
This is the plant that makes the case for a herbarium rather than a herbal. It has an impeccable pedigree — Dioscorides, fifteen centuries of European use, a place in Chinese practice — and it destroys kidneys.
The Belgian episode is worth understanding precisely, because nothing about it required anyone to be careless in an obvious way. Two plants had similar Chinese names, han fang ji and guang fang ji. A supplier sent the wrong one. Nobody in the chain was checking botanical identity, because nobody in the chain thought identity was the risky part. That is the failure mode this whole section is built around.
Nomenclature verified against GBIF backbone taxonomy.