This species is better known in the literature as Polygonum barbatum[
Persicaria omerostroma (Ohki) Sasaki
Polygonum barbatum L.
Polygonum kotoshoense Ohki
Polygonum omerostromum Ohki
Common Name: Joint Weed
Joint weed is a perennial plant producing robust, erect, loosely branched stems 40 - 90cm tall from a creeping, rhizomatous rootstock[
The plant is sometimes gathered from the wild and used locally as a food and medicine.
The whole plant is used as a fish poison[
Although no specific mention has been made for this species, there have been reports that some members of this genus can cause photosensitivity in susceptible people.
Many species also contain oxalic acid (the distinctive lemony flavour of sorrel) - whilst not toxic this substance can bind up other minerals making them unavailable to the body and leading to mineral deficiency. Having said that, a number of common foods such as sorrel and rhubarb contain oxalic acid and the leaves of most members of this genus are nutritious and beneficial to eat in moderate quantities. Cooking the leaves will reduce their content of oxalic acid. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition[
E. Asia - China, Indian subcontinent, Myanmar, Thailand, Malaysia, Indonesia, Vietnam, Philippines, New Guinea.
Depressions in shaded situations at elevations from 1,700 - 1,900 metres in the western Himalayas. Streamsides, wet areas and the sides of water from sea level to 1,300 metres in western and southern China[
Succeeds in an ordinary garden soil[
] but prefers a moisture retentive not too fertile soil in sun or part shade[
]. Repays generous treatment[
Plants seem to be immune to the predations of rabbits[
Tender young leaves and shoots - cooked as a vegetable[
]. They have a somewhat pungent flavour[
The seeds are used to relieve the griping pains of colic[
]. They are used in the treatment of dysentery and cholera[
The root is astringent and cooling[
]. A paste of the root is used externally in the treatment of scabies[
Sap from the pounded leaves is an effective cicatrizant[
]. It is applied externally to wounds[
Seed - sow in situ, germination is usually free and easy.
Division - very easy, larger divisions can be planted out direct into their permanent positions. We have found that it is better to pot up the smaller divisions and grow them on in light shade until they are well established before planting them out[
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