Asteraceae
Calendula officinalis
Pot marigold · Calendula
- Part used
- flower
- Native range
- Probably southern Europe; a cultigen, not certainly known wild
- Morphology
- An annual to about half a metre with sticky aromatic leaves and flat daisy heads in vivid orange and yellow that open and close with the light.
What is in it
Evidence
Reasonable small-trial evidence for topical wound healing and for radiation dermatitis in breast cancer treatment, where one trial found it superior to standard care. Internal uses are untested.
Safety
Very well tolerated topically. Allergy in those sensitive to other Asteraceae. Avoided in pregnancy on traditional grounds.
Regulatory: Permitted as a food colouring 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
A staple of European household medicine and cookery — the pot in pot marigold refers to the cooking pot. Used for wounds, burns, inflamed skin and as a dye and food colouring.
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
Calendula is one of the small number of traditional wound herbs with genuinely encouraging modern evidence, and it is topical evidence — which is the pattern across this collection. Plants applied to skin fare considerably better in trials than plants swallowed.
There is a good reason for that. A topical preparation delivers whatever is in it directly to the tissue being treated, at a concentration you can actually estimate. Anything swallowed has to survive the stomach, the gut wall and the liver first, and most plant constituents do not.
Nomenclature verified against GBIF backbone taxonomy.