Wild yam
Colic root, rheumatism root, dioscorea; German Wilde Yamwurzel; Dioscorea villosa L.
- Known today as
- Dioscorea villosa, of the family Dioscoreaceae, a slender perennial vine of the United States and Canada, twining over fences and bushes, with heart-shaped leaves downy beneath and tiny greenish-yellow flowers. The drug is the hard, woody rhizome, which King’s Dispensatory calls one of the hardest of rhizomes, very difficult to powder or crush, with no odour and little taste beyond a slight acridity. Grieve and King’s both report that it loses its virtue after the first year, so that it should be gathered fresh each year. Grieve records much saponin in the root; King’s that the so-called dioscorein is not a definite principle but simply a dried extract.
- Kind
- Plant, in 1 older authority
- Constituents
- saponin, acrid resin
- Earliest authority here
- Felter and Lloyd, King’s American Dispensatory (1898)
- In other databases
- Plants of the World Online · GBIF · Wikidata
Caution. Neither Grieve nor King’s reports poisoning by this species. King’s notes that the tincture in large doses produces vomiting, and Grieve records that an alkaloid from a Javanese species, D. hirsuta, is a convulsive poison resembling picrotoxin but much feebler. Its safety as a medicine has not been established by the sources read for this entry.
Wild yam: what was it used for?
A remedy for colic. King’s Dispensatory calls it “a favorite therapeutical agent among Eclectic physicians,” used for more than sixty years, and above all “a specific in bilious colic”; it was also given in other colics and painful bowel complaints, in painful cholera morbus with cramps, spasmodic hiccough, painful menstruation, after-pains, and, with the bark of Cornus sericea, in the nausea and vomiting of pregnancy. Grieve repeats it as “perhaps the best relief and promptest cure for bilious colic.”
Wild yam: what does modern science say?
No European monograph covers it, and the searches of Europe PMC made for this entry found no controlled clinical trial of the root itself. An expert panel on cosmetic ingredients, reviewing the matter again in 2023, reaffirmed its 2004 conclusion that wild yam root extract is safe as a cosmetic ingredient in the practices of use and concentrations it describes.
Pharmacognosy & Toxicology
- Constituents
- saponinmuch of it in the root, by Grieve’s account
- acrid resinin which, King’s says, its virtues appear to reside
- Mechanism
- Not established in the sources read for this entry.
- Standing
- There is no European monograph, and no controlled clinical trial of the root was found for this entry. Its extract is judged safe as a cosmetic ingredient (2023).
- Grieve, M. A Modern Herbal, “Yam, Wild.” As published on botanical.com. Read in full · the text read
- Felter, H. W., & Lloyd, J. U. (1898). King’s American Dispensatory, vol. 1, “Dioscorea.” Internet Archive, kingsamericandis01kinguoft. Read in part · the text read
- Raj PS, et al. (2023). Dioscorea Villosa (Wild Yam) Root Extract. International journal of toxicology. PMID 37751575. Abstract read · the text read
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.
Wild yam: what lore surrounds it?
Grieve notes that there are upwards of 150 kinds of Dioscorea, many edible like the potato, and that an Indo-Chinese species is used as a dye in southern China.
Wild yam: what did the older authorities say?
- Felter and Lloyd, King’s American Dispensatory (1898)
- John King admitted that he had called it an antispasmodic “solely for the reason that it cures bilious colic,” and that nearly all remedies had been classified so, “not from any positive knowledge of their action, but from the results following their administration.” The book also tells how, from about 1850, root-diggers mixed a second, knotty rhizome, from a smooth-leaved variety, into the trade; purchasers at first refused it, but as the true root grew scarce they had to accept it, and by the 1890s little of the original drug was to be found, though Eclectic physicians refused the “false” root as without its virtues.
Sources
- Grieve, M. A Modern Herbal, “Yam, Wild.” As published on botanical.com. Read in full · the text read
- Felter, H. W., & Lloyd, J. U. (1898). King’s American Dispensatory, vol. 1, “Dioscorea.” Internet Archive, kingsamericandis01kinguoft. Read in part · the text read
- Raj PS, et al. (2023). Dioscorea Villosa (Wild Yam) Root Extract. International journal of toxicology. PMID 37751575. Abstract read · the text read
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
- Sources
- 3 cited: 1 read in full, 1 read in part, 1 abstract read. 1 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.
Club members can point at a technical term in this entry, such as a constituent, an action, or a word of Jung’s, to read its definition from the source. The Club.
Cite This Entry
Version 1 · first published October 17, 2026
- Chicago
“Wild yam.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified October 17, 2026. https://thethinkingpress.org/materia-medica/wild-yam.
- MLA
“Wild yam.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 17 Oct. 2026, thethinkingpress.org/materia-medica/wild-yam. Accessed 17 Oct. 2026.
- APA
Wild yam. (2026, October 17). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 17, 2026, from https://thethinkingpress.org/materia-medica/wild-yam
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See Also
Sharing saponin
Caulophyllum thalictroides · Saponaria officinalis · Primula vulgaris
Drawing on the same sources: Grieve, Felter
Witch hazel · Violet, lettuce, sow-thistle · Woody nightshade · Arnica · Sorrel, syrup of · Bearberry · the bibliography →
Nearby in the alphabet
Winter-grain mould (Pink and white moulds of grain left in the field over winter) · Wild rue (Peganum harmala) · Witch ball (often silvered or colored, hung in the window) · Wild ginger · Witch bottle · Wild garlic (Allium ursinum) · Wild carrot, seed of (Queen Anne’s lace)
Historical description, not medical advice.
