Persicaria kotoshoensis (Ohki) Sasaki
Persicaria omerostroma (Ohki) Sasaki
Pogalis barbata (L.) Raf.
Polygonum barbatum L.
Polygonum erythrodes Miq.
Polygonum fissum Blume
Polygonum fluviatile Buch.-Ham. ex Endl.
Polygonum kotoshoense Ohki
Polygonum luxurians Danser
Polygonum manoraene Buch.-Ham. ex Endl.
Polygonum omerostromum Ohki
Polygonum ooagariense Masam.
Polygonum raptae Buch.-Ham. ex Endl.
Polygonum rivulare J.Koenig ex Roxb.
Polygonum stoloniferum Blanco
Polygonum strigillosum Zipp. ex Miq.
Common Name: Joint Weed
Persicaria barbata is a perennial plant producing robust, erect to semi-procumbent, 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 plant has been trialled as a potential commercial source of tannins[
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[
Southern Asia -Arabia, Iran, Indian subcontinent, southern China, 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[
Persicaria barbata has a very wide range, from Saudi Arabia and Iran through southern Asia to New Guinea, growing in climates ranging from warm temperate to tropical.
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 dried rhizome is used traditionally as an ingredient of "Easter Ledge Pudding" in the Lake District of Great Britain at Easter[
We have no specific information for this species, but the seed of most, if not all, members of the genus is edible both raw and cooked, and is potentially a good source of amino acids. Unfortunately the seed is also usually rather small and fiddly to utilize[
The seeds are used to relieve the griping pains of colic[
]. They are used in the treatment of dysentery and cholera[
The root contains tannins and 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[
The rhizome is a source of tannins[
Seed - sow spring in a cold frame. Germination is usually free and easy. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in the summer if they have reached sufficient size. If not, overwinter them in a cold frame and plant them out the following spring after the last expected frosts.
Division in spring or autumn. 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 in a cold frame until they are well established before planting them out in late spring or early summer.