Herb latin name: Polygonum tinctorium

Synonyms: Persicaria tinctoria

Family: Polygonaceae (Buckwheat Family)

Medicinal use of Polygonum tinctorium:

The stems and the leaves are antidote, anti-inflammatory, antiphlogistic, antipyretic and depurative. Their use increases the phagocytosis of white blood cells and decreases the permeability of the capillaries. The indigo pigment in the leaves is used. It is used in the treatment of freckles, pimples, erysipelas, mumps, thrush, epidemic protitis, infantile convulsions and high febrile conditions of children. The leaves and fruits are used in Korea to help protect the liver and to treat burns and food poisoning caused by eating fish. The fruits are antidote and febrifuge. The plant is anti-inflammatory.

Description of the plant:


75 cm
(2 feet)

July to

Habitat of the herb:

Weed infested places. Moist valleys and along streambanks at elevations of 200 - 1000 metres in China.

Edible parts of Polygonum tinctorium:

Young plant - cooked. Seed - raw or cooked. It is rather small and fiddly to utilize.

Other uses of the herb:

A blue dye is obtained from the leaves of this plant. The leaves produce about 4 - 5% indigo by hydrolysis and acidification.

Propagation of Polygonum tinctorium:

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.

Cultivation of the herb:

Weed infested places. Moist valleys and along streambanks at elevations of 200 - 1000 metres in China.

Known hazards of Polygonum tinctorium:

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.

Plant information taken from the Plants For A Future.