# 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 > **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. ## 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. ## 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 and toxicology - **triticin**: a fructosan polysaccharide, about 12 per cent of the dried rhizome, built of some thirty fructose units - **fructose**: chief of the free sugars - **emodin**: among anthraquinones found in small amounts **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. ## 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.” ## 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. - Culpeper, N. *The Complete Herbal*, “Dog’s-Grass, Or Cough Grass.” Project Gutenberg, 49513. - 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. - European Medicines Agency, Committee on Herbal Medicinal Products. *Assessment report on Agropyri repentis rhizoma*. EMA/HMPC/113793/2021, 30 March 2022. - 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. - European Medicines Agency, Committee on Herbal Medicinal Products. *Assessment report on Agropyri repentis rhizoma*. EMA/HMPC/113793/2021, 30 March 2022. --- *Couch grass.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-16. The Thinking Press. https://thethinkingpress.org/materia-medica/couch-grass Historical description, not medical advice.