Citron

Statema, B. C. P.

Plant

Citron

Cedro

Known today as: Citrus medica, the large thick-rinded ancestor of the lemon.
Kind: Plant, in 1 older authority
Constituents: limonene, citral, bergapten, and 1 more
Poisoning: Phytophotodermatitis
Earliest authority here: Pliny (AD 23/24–79)
In other databases: Plants of the World Online search · GBIF search · Wikidata search
In the Canale glossary: On the Manner of Discerning and Healing the Bewitched, Appendix A: Treatise One, Part Three, Chapters 2–3: Purgative and Preparative Medicines

Revised October 1, 2026: An older authority added from a text read in full. Version 1, first published September 25, 2026.

Citron: what did Canale use it for?

The seed in purges; the peel in decoctions, pills, and syrup (chs. 4, 6).

Citron: what does modern science say?

Flavor and aroma. No purgative action.

Pharmacognosy & Toxicology

Constituents

limonene ChEMBLthe peel oil
citral ChEMBL
bergapten ChEMBL5-methoxypsoralen, a furanocoumarin of the peel
hesperidin ChEMBLa flavanone

Mechanism

The peel oil is carminative and the pith’s pectin is a bulk laxative; the furanocoumarins make the skin burn in sunlight after handling the peel, which is why citrus pickers blister.

Toxic dose

Safe as food; the oil on the skin before sun gives phototoxic burns.

Syndrome

Phytophotodermatitis

Standing

A food; no monograph. The related bitter orange peel has an EMA monograph for dyspepsia.

Wagner, A. M., et al. (2002). “Bullous phytophotodermatitis associated with high natural concentrations of furanocoumarins in limes.” American Journal of Contact Dermatitis 13. Verified against its record · doi:10.1053/ajcd.2002.29948
Lv, X., et al. (2015). “Citrus fruits as a treasure trove of active natural metabolites.” Chemistry Central Journal 9. Verified against its record · doi:10.1186/s13065-015-0145-9

The abstract of each source, beneath its citation. For Club members. About the Club or sign in.

Constituent names open the compound’s record at PubChem, and “ChEMBL” beside a name opens its record at ChEMBL, the European Bioinformatics Institute’s database of bioactive molecules. Where a mechanism line was checked against ChEMBL (ChEMBL 37, read 1 October 2026), the check is shown with the measured value and its source paper, or says plainly that nothing has been measured. Doses are as the references give them, for description only; this is not medical advice. Each source carries the result of its check against Crossref, PubMed, or the authority’s page: see Verification.

Citron: what lore surrounds it?

Beyond the apothecary, the citron holds a place in Jewish practice of its own: it is the etrog, one of the Four Species held and blessed during Sukkot, a use continuously attested for more than two thousand years.

Citron: what did the older authorities say?

Pliny: Calls the citron tree “the Assyrian, and by some the Median apple,” an antidote against poisons, whose fruit “is never eaten” but whose smell is so strong that it penetrates clothes; and later gives citrons, “either the pulp of them or the pips,” taken in wine as an antidote, the juice as a gargle to sweeten the breath, the pips for pregnant women to chew against qualmishness, and the fruit for a weak stomach, “but it is not easy to eat them except with vinegar.”

Sources

[124] Wu, G. A., et al. (2018). Genomics of the origin and evolution of Citrus. Nature 554: 311–316. doi:10.1038/nature25447 Verified against its record · doi:10.1038/nature25447

Pliny the Elder, Natural History 12.7, 23.56, trans. J. Bostock & H. T. Riley (1855), Perseus Digital Library. Primary text

Verification

Checked

October 1, 2026

Passes

Every sentence read against its sources, in the pass over the remaining 343 entries
The Standing line checked against the authority it names (EMA, WHO, FDA, CITES, Commission E)
Every dated or regulatory claim checked by category across the database
Each quotation from the older authorities checked word for word against the text, read in full

Sources

4 cited: 3 verified against its record, 1 primary text. 3 with the abstract on file.

Corrections

None were needed.

What was checked, how, and what was found is set out on the Verification page. A checked source is one whose record was found; it does not make the entry medical advice.

Cite This Entry

Version 1 · first published September 25, 2026 · last revised October 1, 2026

Chicago: “Citron.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified October 1, 2026. https://thethinkingpress.org/materia-medica/citron.
MLA: “Citron.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 1 Oct. 2026, thethinkingpress.org/materia-medica/citron. Accessed 8 Oct. 2026.
APA: Citron. (2026, October 1). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 8, 2026, from https://thethinkingpress.org/materia-medica/citron

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