Rutaceae
Ruta graveolens
Rue · Common rue · Herb of grace
- Part used
- leafaerial
- Native range
- The Balkan peninsula; naturalised across Europe and beyond
- Morphology
- A blue-green woody subshrub to about a metre with rounded lobed leaves dotted with oil glands and clusters of small yellow flowers. Strongly and unpleasantly aromatic.
What is in it
Evidence
No supported medicinal use. Rutin, named after this genus, is a common flavonoid found far more conveniently elsewhere.
Safety
Severely phototoxic. Handling the plant in sunlight causes phytophotodermatitis — painful blistering burns that scar and pigment for months — and it is a recurring emergency presentation among gardeners. Ingestion causes violent gastrointestinal irritation, and the abortifacient use has killed women: the dose that terminates a pregnancy is close to the dose that causes hepatic and renal failure. Contraindicated absolutely in pregnancy.
Interactions: Furanocoumarins inhibit drug-metabolising enzymes; Additive photosensitivity with other photosensitising drugs
Regulatory: Not a permitted listed-medicine ingredient in Australia.
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
Used for an enormous range of complaints, as a protective and apotropaic herb, in exorcism and blessing — the name herb of grace records the liturgical use — and, persistently and dangerously, as an abortifacient.
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
Rue is the plant that best demonstrates how much of a herbal's contents were once devoted to something nobody advertises now.
Its persistent historical use was as an abortifacient, and it is the most dangerous kind: it works by being toxic enough to threaten the pregnancy, which means the effective dose and the liver-and-kidney-failure dose are not far apart. Deaths are documented into the present, chiefly where legal termination is unavailable. That is not a historical curiosity — it is a live public health problem in several countries.
The phototoxicity is the hazard a gardener meets. Furanocoumarins plus sunlight produce burns that look like scalds and pigment for months, and rue is one of the worst offenders in a European garden, alongside giant hogweed.
Nomenclature verified against GBIF backbone taxonomy.