Herb latin name: Polygonum thunbergii

Synonyms: Persicaria thunbergii

Family: Polygonaceae (Buckwheat Family)

Edible parts of Polygonum thunbergii:

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

Description of the plant:


100 cm
(3 1/4 foot)

July to

Habitat of the herb:

Wet grassy places in lowland and mountains all over Japan.

Propagation of Polygonum thunbergii:

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:

Wet grassy places in lowland and mountains all over Japan.

Medicinal use of Polygonum thunbergii:

None known

Known hazards of Polygonum thunbergii:

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.