Couch grass
Twitch-grass, Scotch quelch, quick-grass, dog-grass, Culpeper’s dog’s-grass or cough grass; Triticum repens L.; Agropyron repens (L.) P. Beauv.; Elymus repens (L.) Gould; in pharmacy Agropyri repentis rhizoma
- Known today as
- A grass of fields and waste places across Europe, northern Asia, Australia, and the Americas, with a slender creeping rhizome that runs far just beneath the surface, “so that it is almost impossible to extirpate it when once established in the soil.” Its flower spikes resemble rye or beardless wheat. The drug is the rhizome, which Grieve describes in commerce as “little shining, straw-coloured, many-edged tubular pieces,” without odour but sweet; the name couch, Grieve says, is supposed to come from the Anglo-Saxon for vivacious, “on account of its tenacity of life.”
- Kind
- Plant, in 2 older authorities
- Constituents
- triticin, fructose, emodin
- Earliest authority here
- Culpeper, The Complete Herbal (1653) (1616–1654)
- In other databases
- Plants of the World Online · GBIF · Wikidata
Caution. Plenty of fluid must be drunk with it, so it is not recommended where a doctor has advised restricting fluids; not under twelve, and for some preparations not under eighteen. See a doctor if fever, painful urination, spasms, or blood in the urine appear.
Couch grass: what was it used for?
A remedy for the bladder and kidneys. Grieve calls it a diuretic demulcent “Much used in cystitis” and catarrh of the bladder, palliating irritation of the urinary passages and relieving gravel, and records that a spring decoction of the roots was once a popular drink to purify the blood, and that in France it remained “a domestic remedy in great repute” as a tisane. The ancients knew a grass with a creeping root-stock like it, the agrostis or gramen, whose root in decoction Dioscorides, as Grieve reports, gave for suppression of urine and stone in the bladder, as did Pliny.
Couch grass: what does modern science say?
The European Medicines Agency’s herbal committee accepts the rhizome as a traditional herbal medicine, “exclusively based upon long-standing use,” to increase the amount of urine and so flush the urinary tract, as an adjuvant in minor urinary complaints (monograph of 2022). Its assessment report finds the rhizome rich in sugars, fructose chief among them, with traces of anthraquinones, and notes the plant’s renaming as Elymus repens. Of the clinical studies, two of a liquid extract in urological disease and one of a water extract in children with urinary stones, it concluded that no conclusions on clinical efficacy could be drawn, though some positive effects were seen.
Pharmacognosy & Toxicology
- Constituents
- Mechanism
- Not established in the sources read for this entry.
- Standing
- European Union herbal monograph (2022): traditional use, “exclusively based upon long-standing use,” to flush the urinary tract in minor urinary complaints.
- European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Agropyri repentis rhizoma (Couch grass rhizome). EMA/HMPC/114726/2021, 30 March 2022. Read in full · the text read
- European Medicines Agency, Committee on Herbal Medicinal Products. Assessment report on Agropyri repentis rhizoma. EMA/HMPC/113793/2021, 30 March 2022. Read in part · the text read
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.
Couch grass: what lore surrounds it?
Dogs, Grieve explains, chew its rough leaves to make themselves vomit, which gave the name dog’s-grass. Withering related that the dried roots, ground to meal, had been made into bread in time of scarcity; in Italy the peasants gathered the roots and sold them in the markets as food for cattle and horses. Readers of Trilby, Grieve adds, will remember Little Billee being dosed with the French couch-grass tisane, “as most Parisians have been.”
Couch grass: what did the older authorities say?
- Culpeper, The Complete Herbal (1653)
- Under Jupiter, and “the most medicinal of all the Quick-grasses,” it opens obstructions of the liver and gall and the stopping of urine and wastes the matter of the stone; the bruised roots knit wounds. For the reader who cannot find it: “watch the dogs when they are sick, and they will quickly lead you to it.” He closes: “although a gardener be of another opinion, yet a physician holds half an acre of them to be worth five acres of Carrots twice told over.”
- Gerard, as Grieve records
- “Although that Couch-grasse be an unwelcome guest to fields and gardens, yet his physicke virtues do recompense those hurts; for it openeth the stoppings of the liver and reins without any manifest heat.”
Sources
- Grieve, M. A Modern Herbal, “Grasses.” As published on botanical.com. Read in full · the text read
- Culpeper, N. The Complete Herbal, “Dog’s-Grass, Or Cough Grass.” Project Gutenberg, 49513. Read in part · the text read
- European Medicines Agency, Committee on Herbal Medicinal Products. European Union herbal monograph on Agropyri repentis rhizoma (Couch grass rhizome). EMA/HMPC/114726/2021, 30 March 2022. Read in full · the text read
- European Medicines Agency, Committee on Herbal Medicinal Products. Assessment report on Agropyri repentis rhizoma. EMA/HMPC/113793/2021, 30 March 2022. Read in part · 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
- 4 cited: 2 read in full, 2 read in part.
- 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.
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Cite This Entry
Version 1 · first published October 16, 2026
- Chicago
“Couch grass.” In Materia Medica, edited by B. C. P. Statema. Version 1. The Thinking Press, 2026–. Last modified October 16, 2026. https://thethinkingpress.org/materia-medica/couch-grass.
- MLA
“Couch grass.” Materia Medica, edited by B. C. P. Statema, version 1, The Thinking Press, 16 Oct. 2026, thethinkingpress.org/materia-medica/couch-grass. Accessed 17 Oct. 2026.
- APA
Couch grass. (2026, October 16). In B. C. P. Statema (Ed.), Materia medica (Version 1). The Thinking Press. Retrieved October 17, 2026, from https://thethinkingpress.org/materia-medica/couch-grass
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See Also
Sharing fructose
Also in Nicholas Culpeper
Cowslip in Nicholas Culpeper · Cleavers in Nicholas Culpeper · Crabs’ eyes in Nicholas Culpeper · Chicory in Nicholas Culpeper · everything Nicholas Culpeper names →
Also in M. Grieve
Echinacea in M. Grieve · Clove in M. Grieve · Fenugreek in M. Grieve · Capsicum in M. Grieve · everything M. Grieve names →
Drawing on the same sources: Grieve, Culpeper
Corn silk · Cubeb · Cordial flowers and fruits · the bibliography →
Nearby in the alphabet
Cornicello · Corn smut · Cramp rings (made from gold and silver offered at the cross) · Cranberry · Coriander (seed and leaf)
Historical description, not medical advice.
