American Bistort

Polygonum bistortoides

Physical Characteristics

Polygonum bistortoides is a PERENNIAL growing to 0.5 m (1ft 8in) by 0.3 m (1ft). See above for USDA hardiness. It is hardy to UK zone 4. 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.

Distribution

Western N. America - Canada to California.

Habitats

Woodland Garden Sunny Edge; Dappled Shade; Bog Garden; Cultivated Beds;

Edible Uses

Edible Parts: Leaves Root Seed Edible Uses: Leaves - raw or cooked. A pleasant acid flavour, they are used as a potherb[183]. Root - raw or cooked[106]. Starchy and rather pleasant[85], the root can be baked or added to soups, stews etc[105, 161, 183, 257]. It was often dried before being used[207]. The raw root is slightly astringent, it becomes sweeter when boiled but is best when baked[212]. Seed - raw or cooked. It is rather small and fiddly to utilize. Edible Uses & Rating (foraging): Leaves are the standout—mild, slightly mucilaginous, fully chewable, good raw or cooked. Seeds are edible as a small grain. Roots are technically edible but extremely bitter from high tannins; even heavy processing gives low culinary return. Edibility rating: 2/5 overall (4/5 for young leaves, 1/5 for roots, 2/5 for seeds) [2-3]. Taste, Processing & Kitchen Notes: Fresh leaves suggest a gentle lettuce/greens profile with a faint slickness; they enrich salads or quick sautés. Roots are pink-purplish with tough reddish-brown skin; bitterness dominates and resists most methods. If roots must be used, slice finely and boil in several changes of water, discarding each liquor; expect much starch loss. Baking doesn’t help. Seeds (tiny achenes) can be gently toasted then simmered into a porridge or added to soups; they’re small, so treat them more like a thickener than a staple. Seasonality (Phenology): Leaves flush late spring to early summer as snow recedes. Flowering July–September; seeds ripen late summer–early fall. Roots can be dug any time ground is workable, though late season reserves may be higher; leaves are best young. Safety & Cautions (Food Use): Roots are very high in tannins—bitter/astringent and potentially irritating in quantity. People sensitive to astringent foods or with kidney issues should avoid heavy root use. Always process roots with repeated boiling and discard liquors. As with many Polygonaceae, moderate portions are prudent. Harvest & Processing Workflow: Leaves: Pick young, wash, eat raw or blanch. Seeds: Shake mature spikes into a bag, winnow chaff, toast lightly, simmer as porridge/thickener. Roots (last resort): Lift small-to-medium crowns, peel skins, slice thin, boil in multiple changes of water; expect limited palatability. Look-Alikes & Confusion Risks: Do not confuse with alpine bistort (B. vivipara), which bears bulblets low on the inflorescence; B. bistortoides does not. In mixed meadows, novices may confuse basal leaves with dock (Rumex) or young false hellebore (Veratrum)—the latter is toxic and has pleated, broad, strongly plicated leaves and very different stature. Traditional/Indigenous Use Summary: Mountain peoples across the West used the young greens as a spring vegetable and the seeds as a minor grain; the roots were sometimes processed extensively as a famine starch, though palatability varies greatly among stands.

Medicinal Uses

Astringent Poultice The root is astringent. A poultice has been used in treating sores and boils[257].

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].