Bistort

(Polygonum bistorta L., Polygonaceae)

Also Called: Dock, Snakeweed.

Description: Large perennial herb more than 1 m (3ft) high with stout, twisted, branched rhizome.
Basal leaves are large, lanceolate, upper surface dark green, lower surface bluish green, margin wavy, petiole triangular in section.
Flowering stem always simple, terminated by a dense, cylindrical flower-spike.
Flowers pink or pale pink with single perianth (not differentiated as calyx and corolla) and protruding stamens.
Flowering: MayJuly.

Part Used: Dried rhizome.

Habitat: In moist pastures of hilly districts in Europe. Scattered throughout Britain, chiefly in northern England and south Scotland.

Collection: Collected preferably in autumn and dried in sun, the larger roots being cut longitudinally.

Constituents and Action: The only active principle is tannin. Anti-inflammatory and astringent.
Used mainly for diarrhoea (also in veterinary medicine), rarely as a gargle or mouthwash for inflammation of the mouth and throat.

Usage: The root is most effective when taken in powder form (2-4 knifepointfuls daily).
An infusion prepared with cold or tepid water (stand 3-10 hours) is also effective.
A decoction (30g (1oz) in 1 litre (1.75 pt) of water) is less active.