Polygonum perfoliatum

Polygonaceae Edible: Leaves, Fruit Potential hazards — see below

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Summary

A annual/perennial growing to 1.8 m (6ft) tall. Hermaphrodite flowers appear July to August, with seeds ripening August to October and pollinated by insects. Adapts to light sandy, medium loamy, and heavy clay soils across mildly acidic to basic pH ranges. Tolerates semi-shade in light woodland or full sun, preferring moist to wet soil conditions.

Description

A herb. It grows each year from seed. The branches are trailing and red-brown. They are angular and have prickles. They can be 2 m long. The leaf stalks are 2-8 cm long and have prickles. The leaves are triangle shaped and 4-6 cm long by 5-8 cm wide.

Edible Uses

Tender young leaves and shoots can be eaten raw or cooked as a vegetable. The ripe fruits are eaten fresh, particularly by children. The seed can also be eaten raw or cooked, though it is quite small and fiddly to work with.

Traditional Uses

The leaves are cooked with fish.

This uses section is brief — help expand it

Medicinal Uses

The whole plant is depurative, diuretic, and febrifuge, and is also used to stimulate blood circulation. A decoction is used in the treatment of dysentery, enteritis, boils and abscesses, poisonous snake bites, haematuria, cloudy urine, and traumatic injuries. The juice of the leaves is applied in the treatment of backaches.

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.

Distribution

It is a tropical plant.

Where It Grows

Asia, China, Myanmar, Nepal, SE Asia,

Cultivation

We have very little information on this species and do not know if it is hardy in Britain, though judging by its native range it should succeed outdoors in most parts of the country. We are not sure if it is a perennial or annual. The following notes are based on the general needs of the genus. 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.

Propagation

Sow seed in spring in a cold frame. Germination is usually straightforward. Once seedlings are large enough to handle, prick them out into individual pots and plant out during summer if they have grown sufficiently. If not, keep them in a cold frame over winter and plant out the following spring after the last expected frosts.

Other Uses

None known

Synonyms

Fagopyrum perfoliatum (L.) Raf.Persicaria perfoliata (L.) H. Gross. and others

Also Known As

Ghumauro kanda, Lann-nyit

References (2)

Aryal, K., Moe, A.T., Hein, P.P., Bay, Y.H.S., Htay, T., Aung, H.W., Shakya, B., Xuefei, Y., Shaoliang, Y. , 2020, Wild and non- cultivated edible plants and their contribution to local livelihoods in Putao, Myanmar. ICIMOD.
Gautam, R. S., et al, 2020, Wild Edible Fruits of Nepal. Int. J. Appl. Sci. Biotechnol. Vol 8(3): 289-304