Common Name:

General Information

Persicaria tinctoria is an erect, usually branched annual plant growing from 50 - 80cm tall[].
The plant has a range of local medicinal applications, the edible leaves and seeds are sometimes gathered from the wild for local use, whilst the plant also yields a blue dye. It used to be cultivated as a dye plant[, ].

Known Hazards

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[].

Botanical References

, ,

Range

E. Asia - southeast China, Vietnam.

Habitat

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

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual
Height	0.75 m
Pollinators	Insects
Cultivation Status	Cultivated, Wild

Cultivation Details

Persicaria tinctoria is native to the warm temperate and subtropical region of southeast China and Vietnam. It can be cultivated in both temperate and tropical zones, though it is frost tender and in temperate regions needs a sufficienly long, frost-free growing season if it is to succeed[].
Succeeds in an ordinary garden soil[], but prefers a moisture retentive not too fertile soil in sun or part shade[]. Requires full sun and a fertile soil[]. Prefers hot humid climates[].
Plants seem to be immune to the predations of rabbits[].

Edible Uses

Young plant - cooked[, ].

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

Medicinal

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[].

Other Uses

A dark blue dye is obtained from the leaves of this plant[, , , ]. It is used for dyeing cotton cloth[]. The leaves produce about 4 - 5% indigo by hydrolysis and acidification[].

Propagation

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 after the last expected frosts.