Family • Polygonaceae - Polygonum hydropiper Linn. - MARSHPEPPER KNOTWEED - Hung la-liao

Scientific names

Polygonum hydropiper Linn.
Polygonum gracile R. Br.
Polygonum oryzetorum Meisn.
Polygonum flaccidum Meisn.
Polygonum hydropiper Meisn.

Common names

Agagat (Bon.)
Buding (Ig.)
Tuba (Bon.)
Annual smartweed (Engl.)
Knotweed (Engl.)
Marshpepper knotweed (Engl.)
Red smartweed (Engl.)
Water pepper smartweed (Engl.)
Hung la-liao (Chin.)


Other vernacular names

ARABIC: Fulful El Mâ´, Zangabîl El Kilâb.
BENGALI: Pakarmul.
BULGARIAN: Piperiče, Piperiche.
CHINESE: Shui liao, La liao cao, Liao.
DANISH: Bidende Pileurt.
DUTCH: Bitterplant, Bittertong, Duizendknoop, Waterpeper.
ESTONIAN: Mõru Kirburohi, Mõru Kirburohi.
FINNISH: Akantatar, Katkeratatar.
FRENCH: Curage, Piment D´eau, Poivre D´eau, Poivre D’eau, Renouée Poivre-D´eau, Renouée.
GERMAN: Pfeffer-Knöterich, Wasserpfeffer, Wasserpfeffer-Knöterich.
GREEK: Neropiperia.
HUNGARIAN: Borsos Keserűfű, Vízibors.
INDONESIAN: Si Tuba Sawah.
ITALIAN: Erba Pepe, Pepe D´asino, Pepe Del Povero, Poligono Acre, Poligono Pepe D´acqua, Poligono Pepe D’acqua, Poligono Piperino
JAPANESE: Asabu-tade, Azebu-tade, Benitade, Ta de, Yanagi tade.
KOREAN: Gaeyeoggwi, Kaeyogwi, Yeo-Ggwi, Yeo-Ggwi-Gwa, Yeoggwi, Yeoggwigwa, Yogwi,
MALAY: Daun Senahun, Rumput Tuboh, Senahun, Tube Seluwang.
NORWEGIAN: Vaspeppar, Vasspepar.
PORTUGUESE: Erva-De-Bicho, Erva-Pessegueira, Persicária, Pimenta De Agua.
RUSSIAN: Gorec Perečnyj, Goretc Perichnyi, Gorets Perechnyj, Perec Vodânoj, Perets Vodyanoj, Vodjanoj Perec, Vodyanoii Peretc.
SPANISH: Pimienta Acuática, Pimienta Acuática, Pimienta De Agua
SWEDISH: Bitterblad, Bitterknäa, Bitterpilört, Bitterpilört, Jungfrutvål, Vattenpeppar, Vattensåpa.
THAI: Phak Phai Nam, Phakchi Mi.

Buding is a smooth, rather robust annual, with tufted or shortly creeping roots. Stems are erect, while the branches are ascending, rather stout and leafy, 30 to 45 cm high, often glandular. Nodes are often swollen. Leaves are lanceolate or oblong-lanceolate, up to 7.5 cm long. Racemes are flexuous, leafy at the base, threadlike, decurved and interrupted. Flowers are pinkish. Nuts are usually three-sided.



– In the Benguet Province of Luzon, in open wet places, along streams, in old rice paddies, etc., at altitudes of 1,200 to 2000 meters.
– Occurs in warmer parts of the world.

– Seed contains polygonic acid and tannin.
– Leaves contain an essential oil, malic acid and phytosterine.
– Rootstock yield an essential oil, oxymethyl-anthraquinone.
– Leaves yield 7.5% protein, 1.9% fat, 8% carbohydrate, 2% ash. Also contains rutin.
– Study of whole plant yielded one new drimane-type sesquiterpenoid, 3 β-angeloyloxy-7-epifutronolide, and one new natural product, polygonumate, along with six known drimane-type sesquiterpenes– [dendocarbin L, (+) winterin, (+) fuegin, changweikangic acid A, futronolide, and 7-ketoisodrimenin.

Additional Sources and Suggested Readings


(1) The Determination of Antibacterial and Antifungal Activities of Polygonum hydropiper (L.) Root Extract / M F Hasan, R Das et al / Advances in Biological Research 3 (1-2): 53-56, 2009

(2) Effect of Polygonum hydropiper Sulfated Flavonoids on Lens Aldose Reductase and Related Enzymes / Hiroyuki Haraguchi et al / J. Nat. Prod., 1996, 59 (4), pp 443–445 / DOI: 10.1021/np9601622

(3) Persistency of bioactive fractions of Indian plant, Polygonum hydropiper as an insect feeding deterrent / A K Tripathi et al / Phytotherapy Research, Volume 13 Issue 3, Pages 239 – 241 / Published Online: 26 May 1999

(4) Effects of crude root extract of Polygonum hydropiper on estrous cycle and induction of reversible sterility in female albino rat / Hazatika A and Sarma H N / J Endocrinol Reprod 11 (2007) 1: 36 – 40

(5) Study on Insecticidal Constituents of Polygonum Hydropiper Linn / China Papers

(6) Inhibitory compound of tyrosinase activity from the sprout of Polygonum hydropiper L. (Benitade)./ Miyazawa M, Tamura N / Biol Pharm Bull. 2007 Mar;30(3):595-7.

(7) Polygonum hydropiper / Plants For A Future.

O. T. OLARU, V. ISTUDOR / Medicine in Evolution Volume XVII, No. 4, 2011

(9) In vitro and in vivo anti-inflammatory activities of Polygonum hydropiper methanol extract. / Yang Y, Yu T, Jang HJ, Byeon SE, Song SY, Lee BH, Rhee MH, Kim TW, Lee J, Hong S, Cho JY. / J Ethnopharmacol. 2012 Jan 31;139(2):616-25. / doi: 10.1016/j.jep.2011.12.003. Epub 2011 Dec 13.

(10) Drimane-type sesquiterpenes from Polygonum hydropiper. / Rajia Sultana, Rashadul Hossain, Achyut Adhikari, Zulfiqar Ali, Sammar Yousuf, Muhammad Iqbal / Planta Medica (impact factor: 2.15). 06/2011; 77(16):1848-51. DOI:10.1055/s-0030-1271178 pp.1848-51

(11) Accumulation characteristics of and removal of nitrogen and phosphorus from livestock wastewater by Polygonum hydropiper / Zheng, Z.C., Li, T.X., Zeng, F.F., Zhang, X.Z., Yu, H.Y., Wang, Y.D., Liu, T. / journal Agricultural Water Management., Volume (Year): 117 (2013)

– Considered anti-inflammatory, astringent, carminative, contraceptive, diaphoretic, diuretic, emmenagogue, stimulant, stomachic, styptic.
– Juice considered diuretic, carminative and anthelmintic.
– Root is bitter, tonic, and stimulating.

Parts used
Roots, leaves.

– Leaves and stems are edible, raw or cooked.
– Seeds made into a peppery condiment as substitute for pepper.
– Young seeds used as salad garnish.
In China, juice is used for itches; also as diuretic, carminative and anthelmintic.
Root used as tonic and stimulant.
Bruised leaves used as poultice and cure for toothache.
Among Russian peasant, used as hemostatic.
Used in all cases of intestinal hemorrhage (pulmonary, gastric, hemorrhoidal, uterine) and used as sedative.
In the United States, once used as an emmenagogue.
In Assam, women used the roots for fertility control.

Study Findings
• Hydropiperoside / Antiferility Activity: Study of methanol extract yielded a novel coumaryl glycoside, hydropiperoside, with other known compounds and an unidentified lactone possessing antifertility activity.
• Antioxidant Flavonoids: Study isolated ten flavonoid compounds from the dried leaves of P. hydropiper. The isolated flavonoids were shown to possess strong antioxidative capabilities. The most powerful was galloyl quercitrin.
• Antibacterial / Antifungal: Study of root extract showed significant antibacterial activities against four gram-positive (B subtilis, B megaterium, S aureus and E aerogenes) and four gram-negative (E coli, P aeruginosa, S typhi and S sonnei) bacteria, with antifungal activity against A fumigatus, A niger, A flavus, C albicans, Rizopus oryzae and T rubrum.
• Lens Aldose Reductase Inhibition: Sulfated flavonoids in Polygonum hydropiper showed potent inhibition against lens aldose reductase. Amont the flavonoids, the most potent was isorhamnetin 3,7-disulfate.
• Antifertility: Study of the methanolic extract of root showed anti-fertility activity in female albino rats.The estrous cycle of the extract treated rats became irregular resulting in failure of gestation. Results suggest the root of PH contains steroidal / estrogenic compounds which affect female reproduction in rats.
• Insecticidal: Study of 5 kinds of Polygonum hydropiper organic solvent extracts showed the ethyl ether extract to have the strongest insecticidal effect. The insecticidal substance was identified as eugenol. Eugenol showed to have stomach toxicity and contact action; it suppressed AchE and GST activity.
• Tyrosinase Activity Inhibitor: Study isolated taxifolin, a tyrosinase inhibitor from the sprout of Polygonum hydropiper. Compared to cosmetic agents arbutin and kojic acid, taxifolin’s tyrosinase inhibitory effect was equal to the latter, more than the former.
• Cytotoxic Activity: Study showed cytotoxic activity, yielding cytotoic compounds soluble in both water and ethanol. Results suggest a therapeutic potential in anti-tumore therapy.
• Estradiol-like Effects: In a study of crude extract of roots , P. hydropiper mimics the effect of estradiol-17ß in the uterine protein profies of adult female albino rats.
• Anti-Inflammatory Effects: Study of methanol extract of Polygonum hydropiper showed strong anti-inflammatory activity. There was dose-dependent suppresionof release of nitric oxide (NO), tumore necrosis factor (TNF)-a, and prostaglandin (PGE2) IN RAW264.7 cells and peritoneal marophages stimulated by lipopolysaccharide.
• Phytoremediation / Nitrogen and Phosphorus: Study showed the mining ecotype (ME) of P. hydropiper removed as high as 87.47% of total nitrogen and 97.63% of total phosphorus. Results show a theoretical basis for use of P. hydropiper for N and P removral from livestock wastewater and presents as a promising species for the phytoremediation of eutrophic waters.