The Greek physician and botanist of the first century, Dioscorides, highlighted the knotweed benefits for people who coughed up blood and women suffering from excessive menstruation. Due to its hemostatic effect (capable of stopping hemorrhages), the Romans called the plant sanguinaria (bloody), which lives on in many places.
- Introduction: Polygonum aviculare or common knotgrass is a plant related to buckwheat and dock. It is also called prostrate knotweed, birdweed, pigweed and lowgrass. It is an annual found in fields and wasteland, with white flowers from June to October.
In the 19th century, when tuberculosis decimated the population of unhealthy towns, knotweed was the object of a profitable business. It was recommended and sold to fight tuberculosis; its hemostatic effect stopped the bronchial and lung hemorrhage of people suffering from tuberculosis. This is a sad example of the mistakes a badly employed phytotherapy may lead to. Fighting the symptoms (bronchial bleeding) was intended to heal the disease (tuberculosis).
We now know the chemical composition and properties that make knotweed and many other plants beneficial. However, if treatments, whether with medicinal herbs or pharmaceutical medicines, are not correctly applied, there is the risk of mistaking the symptoms of the disease.
Knotweed Scientific Facts
- Scientific Name – Polygonum aviculare L.
- Other Names – Knotgrass, beggarweed, bind knotgrass, birdweed, cow grass, common knotweed, crawlgrass, doorweed, ninety-knot, pigweed.
- French – Renouée des oiseaux
- Spanish – Centinodia, hierba nudosa.
- Environment – Common on roadsides and dry soils worldwide.
- Description—This creeping plant of the Polygonaceae family grows on roadsides and crosses roads. It has knotted, thin stems, elongated leaves growing from the knots, and small white, purple, or pink flowers.
- Parts of the plant used medicinally – The entire plant.
Knotweed Benefits
Knotweed contains tannins, flavonoids, silicon, mucilage, and essential oil. Its hemostatic action, which promotes blood coagulation, is mainly due to its high tannin content, which has the property of coagulating proteins. Besides, flavonoids increase the resistance of the cells forming the walls of the blood vessels (especially the capillaries), thus stopping internal bleeding.
The maximum combined effect of both substances is mainly achieved in the digestive system. Thus, knotweed benefits especially suit any inflammation with bleeding that is produced in the intestine and the stomach:
- Gastroenteritis and dysentery (diarrhea accompanied by bleeding): Its effect in these cases is notable because it stops the bleeding and heals the diarrhea.
- Hemorrhagic gastritis and bleeding gastroduodenal ulcers: Due to the severity of hemorrhage, only a physician can prescribe the use of this plant. Knotweed is also helpful in other types of bleeding.
- Mild hemoptysis (bronchial-lung hemorrhage that manifests with blood appearing together with sputum): Bear in mind that the knotweed, though it helps stop the bleeding, does not heal the causative disease (tuberculosis, cancer, etc.).
- Excessive menstruation: Before taking a decoction of knotweed, women have to undergo a gynecological examination.
Due to its essential oil content and other active components, knotweed also has a mild diuretic effect (increases urine production).
How to use Knotweed
- Decoction with 30 to 50 grams of flowering plant (when more effective) per liter of water. Boil for ten minutes and strain; sweeten as you like. Drink four or five cups daily, though this dosage can be exceeded without risk since this plant lacks any toxic effects.
- Powder. Take from two to five grams three times a day.
DISCLAIMER: All content on this website is presented solely for educational and informational objectives. Do not rely on the information provided as a replacement for advice, diagnosis, or treatment from a qualified medical expert. If you are pregnant, nursing, or have any preexisting medical concerns, talk to your doctor before using any herbal or natural medicines.
REFERENCES
- George D. Pamplona-Roger, M.D. “Encyclopedia of Medicinal Plants.” George D. Pamplona-Roger, M.D. Encyclopedia of Medicinal Plants. Ed. Francesc X. Gelabert. Vols. 1 San Fernando de Henares: Editorial Safeliz, 2000. 272, 273. Print. [knotweed benefits]
- https://pubmed.ncbi.nlm.nih.gov/20592901/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4030174/
- https://pubmed.ncbi.nlm.nih.gov/30199916/
Last update on 2025-04-24 / Affiliate links / Images from Amazon Product Advertising API