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Common Name: Alpine Knotweed

General Information

Polygonum alpinum is a perennial plant that can grow up to 1.00 metres tall.
It has edible and medicinal uses.

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

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Range

Europe to E. Asia.

Habitat

Damp meadows, wood margins and mixed grass steppes[]. Open humus-rich slopes, 2200 - 2700 metres in Kashmir[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	1.00 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Succeeds in an ordinary garden soil[] but prefers a moisture retentive not too fertile soil in sun or part shade[]. Grows well near water[]. Repays generous treatment[].
Plants seem to be immune to the predations of rabbits[].
Plants can be invasive but they are easily controlled by spading around the clump[].

Edible Uses

Leaves - raw or cooked[, ]. They have an acid flavour and can be used as a sorrel substitute[]. The chopped leaves and stems have been added to a thick pudding of flour and sugar then eaten[].
Leaf stems - raw or cooked. An acid flavour, they can be cut into sections and used like rhubarb (Rheum spp)[].
The juice from the plant has been sweetened and used as a refreshing drink[].
Seed - raw or cooked. It is rather small and fiddly to utilize.

Medicinal

The whole plant is astringent[]. The raw roots and stem bases have been chewed as a treatment for coughs and colds[].

Other Uses

None known

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 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.