Ranunculaceae
Nigella sativa
Black seed · Black cumin · Kalonji · Habbat al-barakah
- Part used
- seed
- Native range
- Western Asia and the eastern Mediterranean
- Morphology
- A slender annual to about thirty centimetres with finely divided thread-like leaves and pale blue-white flowers, followed by an inflated capsule containing small angular matt-black seeds.
What is in it
Evidence
One of the more actively researched traditional seeds. Meta-analyses report modest reductions in blood pressure, blood glucose and lipids. Trials are mostly small, short and regionally concentrated, and the effect sizes are of uncertain clinical value.
Safety
The seed as food is benign. Concentrated oil at higher doses is associated with hepatotoxicity and nephrotoxicity in case reports. Contact dermatitis from topical oil is common. Thymoquinone has anticoagulant activity.
Interactions: Additive with anticoagulants; Additive with antihypertensives and antidiabetic drugs; May affect drug-metabolising enzymes
Regulatory: Permitted as a food and as a listed medicine ingredient.
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
Found in Tutankhamun’s tomb and recorded in Greek, Islamic and South Asian medicine. Its standing in the Islamic world rests largely on a hadith describing it as a remedy for every disease except death, which is why it is called habbat al-barakah, the seed of blessing.
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
Black seed is the plant whose reputation rests most explicitly on a religious text rather than on a medical one. The hadith describing it as a cure for everything but death is why it occupies the position it does across the Islamic world, and it is a considerably stronger claim than any medical tradition makes for any plant.
That is worth stating plainly and without sneering, because it is also a testable claim in a way most traditional endorsements are not — and the research effort has been substantial. What has come back is a set of small, real, modest metabolic effects, which is neither a vindication of the hadith nor a refutation of it, since the two are not the same kind of statement.
Nomenclature verified against GBIF backbone taxonomy.