American Bistort
Polygonum bistortoides

Family: Polygonaceae

What it is like

Polygonum bistortoides is a PERENNIAL growing to 0.5 m (1ft 8in). See above for USDA hardiness. It is hardy to UK zone 5. It is in flower from July to August. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 0.5

Where it is found

Moist or wet meadows and swamps, seldom below 2500 metres.

Western N. America - Canada to California.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 3

Leaves - raw or cooked. A pleasant acid flavour, they are used as a potherb. Root - raw or cooked. Starchy and rather pleasant, the root can be baked or added to soups, stews etc. It was often dried before being used. The raw root is slightly astringent, it becomes sweeter when boiled but is best when baked. Seed - raw or cooked. It is rather small and fiddly to utilize.

Root: includes bulbs, corms, tubers, rhizomes etc.

Seed: includes nuts, cereals, peas and beans.

Medicine

Rating: 1

The root is astringent. A poultice has been used in treating sores and boils.

Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.

Poultice: A moist, usually warm or hot, mass of plant material applied to the skin in the treatment of burns etc.

Other

Rating:

Food Forest: Plants for Edible Forest Gardens and Food Forests.

How it is grown

Succeeds in an ordinary garden soil but prefers a moisture retentive not too fertile soil in sun or part shade. Repays generous treatment. Plants are growing well at Kew in a moist position by water in the rock garden. Plants seem to be immune to the predations of rabbits. This species is closely related to P. viviparum and P. bistorta. The plant is heat tolerant in zones 8 through 1. (Plant Hardiness Zones show how well plants withstand cold winter temperatures. Plant Heat Zones show when plants would start suffering from the heat. The Plant Heat Zone map is based on the number of "heat days" experienced in a given area where the temperature climbs to over 86 degrees F (30°C). At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 (no heat days) to 12 (210 or more heat days). For example Heat Zone. 11-1 indicates that the plant is heat tolerant in zones 11 through 1.) For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is a clumper with limited spread. The root pattern is rhizomatous with underground stems sending roots and shoots along their length.

Propagating it: 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.

Best place to grow: Woodland Garden Sunny Edge; Dappled Shade; Bog Garden; Cultivated Beds;

Habit: Perennial

Hardiness: 4-8

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

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.

Its other names

Local names

Synonyms

Bistorta bistortoides. (Pursh.)Small.