Polygonum multiflorum Seeds | He Shou Wu
LATIN NAME: Polygonum multiflorum
COMMON NAME: He Shou Wu Seed, Fo-ti, Chinese Knotweed
Plant Profile
The plant climbs by twining, throwing out slender red-brown stems that coil around a support in a single direction. It has no tendrils and no adhesive roots, so it needs a trellis, a fence or a shrub to get off the ground. In deep shade it will climb for several metres before it bothers to flower.
For most of its botanical history the plant sat comfortably in Polygonum. The genus was then split, and the species now appears in the literature as Fallopia multiflora, Reynoutria multiflora or Polygonum multiflorum depending on the author and the year. Seed lists and pharmacopoeias still disagree, so check synonyms before ordering.
The flowers are small, greenish-white and carried in loose branching sprays. What the plant produces is not a true two-seeded fruit but a single achene enclosed by a perianth that grows papery and winged as it ripens, giving the seed its characteristic three-angled, two-lobed outline.
A cold frame or an unheated shed gives the conditions this genus needs to break dormancy: steady, cool and damp throughout. Keep the tray shaded and never let it dry out; a dry spell at this stage costs a whole season.
Plant the young vines 60 cm apart at the foot of the trellis. Tie them in with soft twine as the shoot extends, and pinch the growing tip when it reaches head height to force side shoots. Water well through the first summer and cut the stems hard in late winter to keep the plant within its frame.
Science & Biotechnology
The second chemical family is the anthraquinones: emodin and physcion, with their glycosides. These are the molecules behind the laxative reputation of the raw root and, in the view of many toxicologists, behind the liver signal in the safety literature as well. Their concentration is not fixed: root age, drying temperature and the soil all shift the balance.
Traditional practice distinguishes the raw root from the processed drug. The processing is a repeated cycle of steaming and sun-drying, classically with a decoction of black soybean, until the slices turn dark and slightly sweet. Effective anthraquinone content falls and the stilbene fraction is altered, which is the practical justification for the two-tier approach in the pharmacopoeia.
Reports of liver injury associated with the herb, some serious, prompted alerts from regulators in Europe, North America and Asia. Causality is not fully settled, and some analyses point to interactions or to contaminated product, but the safest reading is that this is a plant to treat as a drug with a real dose-response, not as a salad.
Uses & Benefits
The stilbene glucoside accumulates in the root and is the compound used to standardise commercial root material. It is chemically close to the resveratrol family, which is why it attracts cardiology and neuroprotection researchers, and it is remarkably stable in dried root slices, so it makes a fair marker for quality. Extracts are usually sold as a ratio rather than a purified drug, and the ratio is notoriously loosely defined.
In the kitchen the prepared root is added to slow-cooked soups with black bean and pork, or steeped in wine. The raw root is never used as food. Commercially the trade runs on sliced, dried material for decoction and on concentrated extracts in capsules, and much of the value now lies in brands that publish a stilbene content.
Growing from Seed
Sow the achenes in a deep pot on a gritty, humus-rich mix, barely covering them, and leave the pot outdoors through the winter so that cold and moisture work on the hard coat. A frame or wire to at least 2 m high should be in place before the seedlings are planted out, because the shoot will hunt for a hold within its first season.
Our Take
Grown purely as a climber, this is an agreeable plant, and I would not keep it for the kitchen. If you are curious about the genus, the closely allied Fallopia multiflora entry covers the same taxonomic muddle from the garden side, while the notorious Japanese knotweed shows what happens when a fast Polygonaceae rhizome escapes a wall. For a harmless knotweed-family crop in the same bed, grow buckwheat instead.
Related Reading
Readers interested in He Shou Wu Seed frequently explore these as well: