Persicaria bistorta

Other names: Hadí kořen

Dense pink spike; rhizome in tradition.

Basal triangular leaves, underground rhizome.

Family: Polygonaceae
Plant type: Perennial herb
Safety level (indicative): Generally recognised as safe

What the safety levels mean (expand legend)

Generally recognised as safe. Often a common herb with reasonable harvest and use; still read the specific warnings on the card.
Information. Primarily informational — details in the text and warnings below matter most.
Caution. Needs extra care (dose, duration, sensitive groups, interactions).
Risky. Significant risks — verify sources, contraindications and professional guidance.
Not for home experimentation. Not suitable to experiment with at home without knowledge and certainty.
High risk for internal use. Particular risk with internal use (e.g. alkaloids); avoid prolonged or irresponsible dosing.
Not specified. Level not filled in yet — rely on individual warnings and links below.

Rdesno hlíznaté — habitus rostliny (Wikimedia Commons). — Fotografie na Wikimedia Commons (CC BY-SA 3.0).
Plant habit

Quick overview

A practical summary; details are in the sections below.

Safety grade: Generally recognised as safe·details
Scientific sources on the card: Yes — sources are listed with claims·Science section
When and what to harvest: Root — March–May
Full harvest section
Processing methods: Decoction, Syrup, Honey macerate
All methods and recipes on the card
Topics and symptoms: Menstrual comfort, Women's topics in folk herbalism
Topics section · Symptoms overview

Identification and mix-ups

Cylindrical inflorescence on a bare scape.

Possible mix-ups and risks

Related persicarias by rhizome and spike.

Similar herbs

No related herbs are linked yet.

Topics and symptoms

More topics are in the symptoms and topics overview.

Menstrual comfort
Traditional· Traditional / cultural framing
Women's topics in folk herbalism
Traditional· Traditional / cultural framing

Geographic occurrence

Czechia
Common (expected wild occurrence in the region)
Austria
Common (expected wild occurrence in the region)
Germany
Common (expected wild occurrence in the region)
Hungary
Common (expected wild occurrence in the region)
Poland
Common (expected wild occurrence in the region)
Slovakia
Common (expected wild occurrence in the region)

Harvest

RootMarch–May
jaro
Region: Czechia
Notes: Harvest note (full translation pending): Oddenek po rozmrznuti pudy; cista mista.

Storage

Drying(Leaf)
Sušený rostlinný materiál uchovávej v uzavřené nádobě.
Light:
Mimo přímé UV.
Moisture:
Nízká relativní vlhkost.

Processing methods on this herb card

Decoction(Root)Suitability: Medium suitability
Longer simmering of plant material in water.
Full method description (from the catalogue)
A decoction is made by simmering plant material in water — often around 10–20 minutes depending on tradition and plant part. Denser parts (roots, bark, some seeds) are often prepared more reliably this way than with a short infusion.
Compared with an infusion it can extract more compounds, but also more tannins or bitterness; the flavour profile differs from a delicate tea. Combine this overview with the herb card for suitable plant part and contraindications.
Traditional context for this method: yes·Scientific context for this method: no
Procedure (recipe)
Silverweed rhizome decoction
About 15 min · Difficulty: Beginner
1. For 500 ml water use about 2 tsp dried, chopped rhizome (from a confident harvest).
2. Simmer 10–15 minutes under a lid, then strain.
3. Drink short-term in small portions — expect a strong astringent taste.
Not a substitute for medical care; with constipation or tannin sensitivity, use a gentler approach.
Why this way (extraction / behaviour of constituents)
Home preparation following this recipe is mainly educational and cultural; it should not be assumed to match the extractive or safety profile of registered medicines or standardized extracts. Check specific effects, drug interactions, and contraindications on the herb card and with your clinician if you use prescription drugs.
What is typically released
orientační domácí extrakce — profil závisí na teplotě, času řezu a poměrech
Solvent / water
mediální složení (voda, alkohol, olej, med…) viz jednotlivé kroky
After preparation
po přípravě uchovávej hygienicky a podle typu výrobku (chlad, světlo, alkohol)
Extra literature for the recipe
- Vyhledávání studií (PubMed apod.)Konkrétní vědecká tvrzení ověř na kartě byliny a v primární literatuře.
Syrup(Root)Suitability: Medium suitability
Decoction or infusion with sweetener and reduction; shelf life depends on sugar and storage.
Full method description (from the catalogue)
Syrups combine a herbal base with sugar or honey and often a short boil to concentrate and improve hygiene. Preservation depends strongly on water content, sugar level, and bottling practice.
Home syrups may fall under food rules; store in the fridge after opening per recipe.
Traditional context for this method: yes·Scientific context for this method: no
Procedure (recipe)
Silverweed rhizome syrup
About 50 min · Difficulty: Beginner
1. Simmer 2–3 tsp chopped dried rhizome in 400 ml water under a lid for about 15 minutes, then strain.
2. Stir in honey or dissolve sugar with gentle warming.
3. Store refrigerated and dilute well; expect a strong astringent note for short-term use.
Not medical care; with constipation or tannin sensitivity, use a weaker brew.
Why this way (extraction / behaviour of constituents)
Home preparation following this recipe is mainly educational and cultural; it should not be assumed to match the extractive or safety profile of registered medicines or standardized extracts. Check specific effects, drug interactions, and contraindications on the herb card and with your clinician if you use prescription drugs.
What is typically released
orientační domácí extrakce — profil závisí na teplotě, času řezu a poměrech
Solvent / water
mediální složení (voda, alkohol, olej, med…) viz jednotlivé kroky
After preparation
po přípravě uchovávej hygienicky a podle typu výrobku (chlad, světlo, alkohol)
Extra literature for the recipe
- Vyhledávání studií (PubMed apod.)Konkrétní vědecká tvrzení ověř na kartě byliny a v primární literatuře.
Honey macerate(Root)Suitability: Medium suitability
Macerating plant material in honey (a honey conserve).
Full method description (from the catalogue)
Honey as a maceration medium creates a viscous mixture with its own biochemistry: water activity, acidity, and enzymes influence shelf life and flavour. Traditionally it is used with delicate flowers or herbs when you want aroma bound into honey.
Infant botulism guidance for honey and honey safety in general sit outside a single herb page; maceration time, ratios, and storage must follow a vetted recipe and source, not this general overview alone.
Traditional context for this method: yes·Scientific context for this method: no
Procedure (recipe)
Silverweed rhizome honey
About 35 min · Difficulty: Beginner
1. Fill about one quarter of the jar with finely chopped dried rhizome and cover with honey.
2. Macerate 3–4 weeks, then strain — expect a strong astringent note.
Maceration takes weeks; short-term use as drops in tea, not large spoonfuls.
Why this way (extraction / behaviour of constituents)
The rhizome is rich in tannins and other polar metabolites; slow maceration in honey gradually releases material into a dense hydrophilic medium. Astringency and flavour intensity rise with plant load — a home macerate is not the same as a pharmaceutical tincture.
What is typically released
Taniny a polární frakce postupně do medu.
Solvent / water
Med; macerace řádově týdny.
After preparation
Po scedění chladně; sleduj krystalizaci medu a mikrobiální známky.
Extra literature for the recipe
- Vyhledávání studií (PubMed apod.)Obecný vstup; konkrétní tvrzení ověř na kartě byliny.

Traditional / spiritual use

Kept separate from science — entries are cultural or symbolic, not medical advice.

Related guides in the library

Traditional folk context
General
The herb appears in older folk customs referenced on Czech cards. This note is cultural memory and seasonal storytelling — not a dosing guide, clinical indication, or substitute for the safety section.
Form:
různé
Claim strength:
Tradition
Source note:
Cultural framing only.

Scientific notes

Each claim lists a study type and a source (URL or DOI) where available. Dose notes from the literature are informational only.

How to read evidence strength and study type labels

Labels summarise how the catalogue entry is tagged — they are not a medical verdict on efficacy. For every row, read the summary, limitations and source link.

Evidence strength

Evidence level not specified: The author did not grade the record; judge from the summary, limitations and source link.
Narrative / orientational literature: Descriptive or expert literature without controlled group comparison — context rather than proof of effect.
Weak evidence: Study or conclusion with major methodological limits; treat only as a pointer for further reading.
Preliminary findings: First or smaller studies — interesting direction, not the final word on efficacy or safety.
Moderate strength of evidence: Moderate strength by study design; sample and context limits still apply.
Stronger evidence: Stronger design or consistency of results within the study’s stated limits.
Review article: A review summarises multiple sources; quality depends on review method and field.

Study type

Narrative / expert text: Expert text or overview without a classical study design.
In vitro study: Cell culture or test-tube experiment — does not show an effect in the body.
Animal study: Animal model — transfer to humans is not automatic.
Observational study: Observing groups without random treatment assignment; confounding is possible.
Clinical trial: Human clinical trial; sample size and control group matter.
Randomised controlled trial: Randomised controlled trials are among the stronger designs when well conducted.
Review study: A review aggregates multiple papers — quality depends on selection rules.
Systematic review: Systematic review with explicit search and selection methodology.
Meta-analysis: Statistical pooling of studies; outcome depends on input data and heterogeneity.
Regulatory assessment / monograph (EMA, WHO…): Regulatory body summary for a herbal product — different context from a single RCT; often about products, not home tea.
Expert monograph (herbal preparations): Structured literature summary for a plant or drug — quality depends on author and edition year.

Evidence summary (full translation pending): O ucincich a bezpecnosti existuje odborna literatura; zaznam je orientacni a nenahrazuje peci odbornika.
Evidence level not specifiedNarrative / expert text
Limitations: Limitations (translation pending): Seed katalogu — dopln konkretni studie podle obsahu.
Vyhledávání studií (PubMed apod.)

Images

The main photo is in the card header. More images will appear here when available.

Safety

What the warning types mean

The type on each warning helps group themes — it does not replace the separate severity badge.

Internal use: Risks from swallowing, extracts, duration of use or concentration for internal use.
Interactions / medicines: Possible effect on medicines or concurrent treatment — check sources and a professional.
Raw plant parts: Raw, unripe or poorly prepared plant parts can be dangerous.
Toxins and regulation: Toxic constituents or regulated compounds (e.g. in distillates).
Contact with the plant: Skin or mucosa irritation from contact with fresh plant or sap.
Allergy: Allergic reactions, often linked to family sensitisation.
Harvesting and contamination: Contamination, species mix-ups or harvesting from unsuitable places.

No structured safety records yet.