We depend on donations from users of our database of over 8000 edible and useful plants to keep making it available free of charge and to further extend and improve it. In recent months donations are down, and we are spending more than we receive. Please give what you can to keep PFAF properly funded. More >>>

Follow Us:

 

Polygonum aviculare - L.

Common Name Knotweed, Prostrate knotweed
Family Polygonaceae
USDA hardiness 4-8
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[238].
Habitats Waste places, roadsides, railway embankments and the coast[9]. A common garden weed[1].
Range Throughout Europe, including Britain, to Temperate Asia.
Edibility Rating    (2 of 5)
Other Uses    (1 of 5)
Weed Potential Yes
Medicinal Rating    (3 of 5)
Care (info)
Fully Hardy Moist Soil Semi-shade Full sun
Polygonum aviculare Knotweed,  Prostrate knotweed


http://commons.wikimedia.org/wiki/File:Polygonum_aviculare_Sturm63.jpg
Polygonum aviculare Knotweed,  Prostrate knotweed
http://commons.wikimedia.org/wiki/User:Dalgial

 

Translate this page:

Summary


Physical Characteristics

 icon of manicon of flower
Polygonum aviculare is a ANNUAL growing to 0.3 m (1ft).
See above for USDA hardiness. It is hardy to UK zone 5. It is in flower from June to October, and the seeds ripen from August to October. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. The plant is self-fertile.
It is noted for attracting wildlife.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid soils.
It can grow in semi-shade (light woodland) or no shade. It prefers moist soil. The plant can tolerate maritime exposure.

UK Hardiness Map US Hardiness Map

Synonyms

P. heterophyllum. P. littorale.

Habitats

Edible Uses

Edible Parts: Leaves  Seed
Edible Uses: Tea

Young leaves and plants - raw or cooked[105, 177]. Used as a potherb[183], they are very rich in zinc[179]. A nutritional analysis is available[218]. Seed - raw or cooked. Rather small and fiddly to utilize, they can be used in all the ways that buckwheat (Fagopyrum esculentum) is used, either whole or dried and ground into a powder for use in pancakes, biscuits and piñole[4, 55, 106, 161, 183]. The leaves are a tea substitute[183].

References   More on Edible Uses

Composition
Figures in grams (g) or miligrams (mg) per 100g of food.
Leaves (Fresh weight)
  • 0 Calories per 100g
  • Water : 81.6%
  • Protein: 1.9g; Fat: 0.3g; Carbohydrate: 10.2g; Fibre: 3.5g; Ash: 3.5g;
  • Minerals - Calcium: 0mg; Phosphorus: 0mg; Iron: 0mg; Magnesium: 0mg; Sodium: 0mg; Potassium: 0mg; Zinc: 0mg;
  • Vitamins - A: 0mg; Thiamine (B1): 0mg; Riboflavin (B2): 0mg; Niacin: 0mg; B6: 0mg; C: 0mg;
  • Reference: [ 218]
  • Notes:

Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.
Anthelmintic  Antiphlogistic  Astringent  Cardiotonic  Cholagogue  Diuretic  Dysentery  Emetic  
Emollient  Expectorant  Febrifuge  Haemostatic  Lithontripic  Purgative  TB  
Vasoconstrictor  Vulnerary

Knotweed is a safe and effective astringent and diuretic herb that is used mainly in the treatment of complaints such as dysentery and haemorrhoids. It is also taken in the treatment of pulmonary complaints because the silicic acid it contains strengthens connective tissue in the lungs[254]. The whole plant is anthelmintic, astringent, cardiotonic, cholagogue, diuretic, febrifuge, haemostatic, lithontripic and vulnerary[4, 7, 9, 21, 53, 147, 172, 176, 178]. It was formerly widely used as an astringent both internally and externally in the treatment of wounds, bleeding, piles and diarrhoea[4]. Its diuretic properties make it useful in removing stones[4]. An alcohol-based preparation has been used with success to treat varicose veins of recent origin[7]. The plant is harvested in the summer and early autumn and is dried for later use[9]. The leaves are anthelmintic, diuretic and emollient[218]. The whole plant is anthelmintic, antiphlogistic and diuretic[218]. The juice of the plant is weakly diuretic, expectorant and vasoconstrictor[218]. Applied externally, it is an excellent remedy to stay bleeding of the nose and to treat sores[4]. The seeds are emetic and purgative[4, 240]. Recent research has shown that the plant is a useful medicine for bacterial dysentery. Of 108 people with this disease, 104 recovered within 5 days when treated internally with a paste of knotweed[254].

References   More on Medicinal Uses

Now available: PLANTS FOR YOUR FOOD FOREST: 500 Plants for Temperate Food Forests and Permaculture Gardens.

An important new book from PFAF. It focuses on the attributes of plants suitable for food forests, what each can contribute to a food forest ecosystem, including carbon sequestration, and the kinds of foods they yield. The book suggests that community and small-scale food forests can provide a real alternative to intensive industrialised agriculture, and help to combat the many inter-related environmental crises that threaten the very future of life on Earth.

Read More

FOOD FOREST PLANTS

Other Uses

Dye

Yields a blue dye that is not much inferior to indigo[115]. The part used is not specified, but it is likely to be the leaves. Yellow and green dyes are obtained from the whole plant[168]. The roots contain tannins, but the quantity was not given[223].

Special Uses

Attracts Wildlife

References   More on Other Uses

Cultivation details

Succeeds in an ordinary garden soil[1] but prefers a moisture retentive not too fertile soil in sun or part shade[200]. Repays generous treatment, in good soils the plant will cover an area up to a metre in diameter[1, 4]. Prefers an acid soil[20]. Dislikes shade. Knotweed is a common and invasive weed of cultivated ground[7]. It is an important food plant for the caterpillars of many species of butterflies[30]. It also produces an abundance of seeds and these are a favourite food for many species of birds[4]. Plants seem to be immune to the predations of rabbits[233]. The flowers have little or no scent or honey and are rarely visited by pollinating insects. Self-fertilization is the usual method of reproduction, though cross-fertilization by insects does sometimes occur[4]. The plant also produces cleistogomous flowers - these never open and therefore are always self-fertilized[4]. The plant is very variable and is seen by most botanists as an aggregate species of 4 very variable species, viz. - P. aviculare. L.; P. boreale. (Lange.)Small.; P. rurivacum. Jord. ex Box.; and P. arenastrum. Box[17].

References   Carbon Farming Information and Carbon Sequestration Information

Temperature Converter

Type a value in the Celsius field to convert the value to Fahrenheit:

Fahrenheit:

image

The PFAF Bookshop

Plants For A Future have a number of books available in paperback and digital form. Book titles include Edible Plants, Edible Perennials, Edible Trees, and Woodland Gardening. Our new book to be released soon is Edible Shrubs.

Shop Now

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.

Other Names

If available other names are mentioned here

Native Plant Search

Search over 900 plants ideal for food forests and permaculture gardens. Filter to search native plants to your area. The plants selected are the plants in our book 'Plants For Your Food Forest: 500 Plants for Temperate Food Forests and Permaculture Gardens, as well as plants chosen for our forthcoming related books for Tropical/Hot Wet Climates and Mediterranean/Hot Dry Climates. Native Plant Search

Found In

Countries where the plant has been found are listed here if the information is available

Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

Conservation Status

IUCN Red List of Threatened Plants Status :

Related Plants
Latin NameCommon NameHabitHeightHardinessGrowthSoilShadeMoistureEdibleMedicinalOther
Polygonum alaskanumAlaska Wild RhubarbPerennial1.8 -  LMHSNM21 
Polygonum alpinumAlpine Knotweed, Alaska wild rhubarbPerennial1.0 4-8  LMHSNM21 
Polygonum amphibiumWillow Grass, Water knotweed, Longroot smartweed, Water smartweedPerennial0.3 4-8  LMHSNWeWa121
Polygonum arenastrumSmall-Leaved Knotweed, Oval-leaf knotweedAnnual0.3 4-8  LMHSNM231
Polygonum barbatumJoint WeedPerennial0.8 -  LMHSNM11 
Polygonum bistortaBistort, Meadow bistort, SnakeweedPerennial0.5 4-7 FLMHSNMWe332
Polygonum bistortoidesAmerican BistortPerennial0.5 4-8  LMHSNM31 
Polygonum bungeanumBunge's smartweedAnnual0.8 0-0  LMHSNM10 
Polygonum coccineumWater SmartweedPerennial0.5 4-8  LMHSNWeWa10 
Polygonum conspicuum Perennial0.6 -  LMHSNM10 
Polygonum convolvulusBlack BindweedAnnual1.2 0-0  LMHSNM100
Polygonum divaricatum Perennial1.0 -  LMHSNDM10 
Polygonum douglasiiKnotweed, Douglas' knotweed, Austin knotweed, Engelmann's knotweed, Johnston's knotweed, Large knoAnnual0.3 0-0  LMHSNDM20 
Polygonum dumetorumClimbing false buckwheatAnnual1.8 0-0  LMHSNM11 
Polygonum equisetiforme Perennial1.0 7-10  LMHNDM102
Polygonum fugax Perennial0.0 -  LMHSNM30 
Polygonum hydropiperSmartweed, Marshpepper knotweedAnnual0.8 0-0  LMHNWeWa221
Polygonum japonicumJapanese Knotweed, Mexican Bamboo, Japanese KnotweedPerennial3.0 4-10 FLMHSNM333
Polygonum lapathifoliumCurlytop KnotweedAnnual0.8 4-8  LMHSNMWe111
Polygonum limosum Perennial1.8 -  LMHSNM10 
Polygonum longisetumOriental lady's thumbAnnual0.5 0-0  LMHSNMWe10 
Polygonum maackianum Annual0.8 -  LMHSNMWe10 
Polygonum manshurienseAsian BistortPerennial0.8 -  LMHSNMwe01 
Polygonum microcephalum Perennial0.5 -  LMHSNM10 
Polygonum minusPygmy smartweedAnnual0.3 0-0  LMHSNMWe10 
Polygonum molle Perennial2.5 6-9 FLMHSNM212
Polygonum multiflorumHe Shou Wu, Tuber fleeceflowerPerennial Climber4.5 6-9  LMHSNM23 
Polygonum nepalenseNepalese smartweedAnnual0.3 0-0  LMHSNMWe111
Polygonum orientalePrince's Feather, Kiss me over the garden gateAnnual1.5 0-0  LMHSNM220
12

Growth: S = slow M = medium F = fast. Soil: L = light (sandy) M = medium H = heavy (clay). pH: A = acid N = neutral B = basic (alkaline). Shade: F = full shade S = semi-shade N = no shade. Moisture: D = dry M = Moist We = wet Wa = water.

 

Print Friendly and PDF

Expert comment

Author

L.

Botanical References

17

Links / References

For a list of references used on this page please go here

Readers comment

J V Cooper   Fri Jul 21 2006

I have read all this information and still have no idea what the plant looks like. A picture would be very good.

Ginger good   Tue Aug 1 2006

Where can I purchase a small amount of Polygonum aviculare to use in a tea?

Jean-Pierre   Fri Dec 29 2006

Very good information. Is it possible to add on your site where we could buy seeds or even the plant for medicinal purpose? Many thanks.

   Nov 29 2010 12:00AM

My friend is of Lebanese origin, and her family has been using Prostrate Knotweed as a salad for generations. It grows as a weed in the garden and they cut it off at ground level, wash it and dry it. Then break it into bite-size pieces. Then add to fresh cut-up tomatoes, oil, vinegar, salt, pepper, and perhaps a little dried mint. Then pick it up with bite-size pieces of Syrian bread or other flat bread and enjoy. Her family calls prostrate knotweed 'farfeen' (sp?)

Add a comment

If you have important information about this plant that may help other users please add a comment or link below. Only comments or links that are felt to be directly relevant to a plant will be included. If you think a comment/link or information contained on this page is inaccurate or misleading we would welcome your feedback at [email protected]. If you have questions about a plant please use the Forum on this website as we do not have the resources to answer questions ourselves.

* Please note: the comments by website users are not necessarily those held by PFAF and may give misleading or inaccurate information.

To leave a comment please Register or login here All comments need to be approved so will not appear immediately.

Subject : Polygonum aviculare  
© 2010, Plants For A Future. Plants For A Future is a charitable company limited by guarantee, registered in England and Wales. Charity No. 1057719, Company No. 3204567.