Botany
Polygonum pubescens is a perennial herb, much taller than Polygonum hydropiper, up to 75 centimeters tall. Leaves are stalkless, 5 to 15 centimeters long, smooth or hairy. Pinkish-red flowers are borne in drooping racemes, 15 centimeters long, and slender. Nut is small, black, and minutely granular.

Distribution
- In swampy places at low altitude in Cagayan Province in Luzon.
- Also occurs in India, China, Taiwan and Malaya.

Constituents
- Plant yields anthocyanin (cyanidin glycoside, peonidin glycoside), flavonol (myricetin 3-0-rhamnoside, quercetin 3-O-(2"-galloylrhamnoside), quercetin 3-O-rhamnoside. (4)
- Study of petroleum ether and ethyl acetate extracts of aerial parts yielded 22 compounds, a new phenylpropanoide ester (1) and 21 known compounds. (5)

Properties
- Emmenagogue, abortifacient.

Uses
Edibility
- Leaves used as potherb or seasoning.
Folkloric
- In China the bruised plant is applied locally to blistered and swollen feet.
- Used for snake bites.
- Plant decoction, combined with onion, used as styptic i.e., to stop wound bleeding.
- Also used as emmenagogue and abortifacient.
Others
- In India's Arunachal Pradesh, whole plant paste is thrown into the stream to stupefy the fish, make them float up for an easy catch. (1)

Studies
• Phytoremediation / Cadmium: Study evaluated the accumulation characteristics of Cd in Polygonum pubescens. Under all test concentrations, Cd content in the roots and shoots exceeded 100 mg/kg and the enrichment coefficient over 1. Results showed P. pubescens has high tolerance and accumulation capacity of Cd, with a potential on phytoremediation of Cd-contaminated soil. (2)
• Phytoremediation / Manganese: Study evaluated the Mn tolerance and accumulation of Polygonum pubescens under different Mn concentrations. P. pubescens showed certain tolerance to Mn contaminated soil.
• New Phenylpropanoid Ester: Study of aerial parts yielded 22 compounds, i.e., a new phenylpropa-noide ester and 21 known compounds. Sixteen compounds were evaluated for cytotoxic and anti-inflammatory activities. Some compounds showed effects on different targets. (5)

Availability
Wild-crafted.

Additional Sources and Suggested Readings
(1)
Traditional knowledge of Adi tribe of Arunachal Pradesh on plants / R C Srivastava and Adi community / Indian Journ of Traditional Knowledge, Vol 8(2), April 2009, pp 146-153
(2)
Accumulation characteristics of Cd in Polygonum pubescens Bl. / Deng Hua / Agricultural Science and Technology (Jun. 2010)
(3)
Sorting Polygonum names / /Maintained by: Michel H. Porcher / MULTILINGUAL MULTISCRIPT PLANT NAME DATABASE / Copyright © 1995 - 2020 / A Work in Progress. School of Agriculture and Food Systems. Faculty of Land & Food Resources. The University of Melbourne. Australia.
(4)
Flavonoid Properties of five Families newly Incorporated into the Order Caryophyllales (Review) / Tsukasa Iwashina / Bull. Natl. Mus. Nat. Sci., Ser. B, 39(1), pp. 25–51, February 22, 2013
(5)
A new sucrosephenylpropanoid ester from Polygonum pubescens Blume / Qiang Liu, Bin Li, Jianping Zhao, Shabana I Khan, Wen-bin Lu, Ting Zeng et al / Natural Product Research, 2017; 31(15) / https://doi.org/10.1080/14786419.2017.1289208