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Verbascum thapsus

Verbascum thapsus

Other names: Divizna

Tall stem with a yellow flower spike.

Basal rosette of woolly leaves; flowering stem in year two.

Family
Scrophulariaceae
Plant type
Biennial 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.
Divizna velkokvětá — 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
  • Flower — May–August
Full harvest section
Processing methods

Herbal infusion (tea), Herbal oil, Syrup

All methods and recipes on the card
Topics and symptoms

Breathing comfort, Common cold — overall comfort, Cough and mucus…

Topics section · Symptoms overview

Identification and mix-ups

Tubular corollas in a dense spike.

Possible mix-ups and risks

Smaller mulleins and verbascum look-alikes.

Similar herbs

No related herbs are linked yet.

Topics and symptoms

More topics are in the symptoms and topics overview.

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)

  • Canada

    Common (expected wild occurrence in the region)

  • Australia

    Common (expected wild occurrence in the region)

Harvest

  • FlowerMay–August

    léto

    Region: Czechia

    Notes: Harvest note (full translation pending): Kvetenstvi v plnem kvetu.

Storage

  • Drying(Leaf)

    Sušený rostlinný materiál uchovávej v uzavřené nádobě.

    Light:
    Mimo přímé UV.
    Moisture:
    Nízká relativní vlhkost.

Processing methods on this herb card

  • Herbal infusion (tea)(Flower)Suitability: High suitability

    Infusion or brief extraction in hot water; usually without long boiling.

    Full method description (from the catalogue)

    In the narrow sense, “tea” often means an infusion: you pour water just off the boil over the dried plant matter and let it steep for a few minutes. Temperature, steep time, and the herb-to-water ratio change both flavour and what dissolves into the liquid.

    Compared with a decoction, heat exposure is shorter and gentler; tender leaves and flowers are often better as an infusion than with prolonged simmering. For each herb, always follow the plant card for suitable plant part, preparation, and safety notes — general rules never replace species-level judgement.

    Traditional context for this method: yes·Scientific context for this method: no

    Procedure (recipe)

    Great mullein flower tea

    About 12 min · Difficulty: Beginner

    1. Use 1 teaspoon of dried corollas per cup (dried flowers are bulky).
    2. Pour boiling water, cover, and steep 8–12 minutes.
    3. Strain — gently sweet; watch for irritating hairs on fresh material if you harvest yourself.

    Why this way (extraction / behaviour of constituents)

    Home preparation following this recipe is mainly educational and cultural in intent; it does not automatically match the extraction or safety profile of registered medicines or standardized extracts. Check specific effects, drug interactions, and contraindications on the herb card and with a clinician if you use medication.

    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

  • Herbal oil(Flower)Suitability: Medium suitability

    Macerating herbs in a vegetable oil (cold or with gentle heat).

    Full method description (from the catalogue)

    Herbal oil is made by steeping dried or fresh material in oil (e.g. olive, sunflower) over time, sometimes with gentle warming. The result is not steam-distilled essential oil — it is a different extract type and usage (often topical or culinary per recipe).

    Temperature, light, and material moisture affect shelf life; rancid oil must be discarded.

    Traditional context for this method: yes·Scientific context for this method: no

    Procedure (recipe)

    Mullein flower oil

    About 40 min · Difficulty: Intermediate

    1. Fill a jar with flowers and cover with olive or almond oil so they stay submerged.
    2. Macerate 3–4 weeks in a warm sunny spot, then strain through cloth.
    3. Use on intact skin only; be cautious near sensitive mucosa because of flower hairs.

    Maceration takes weeks; do not put into the ear without clinician guidance; stop if irritation appears.

    Why this way (extraction / behaviour of constituents)

    Mullein florets carry irritant hairs; oil maceration can suspend fine plant particles. Use on intact skin only; avoid mucous membranes and the ear canal unless a clinician advises you individually.

    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

  • Syrup(Flower)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)

    Mullein flower syrup

    About 50 min · Difficulty: Beginner

    1. Cover flowers with a light hot sugar syrup, or simmer briefly with water and sugar, then cool overnight.
    2. Strain, add lemon juice, reheat briefly, and bottle.
    3. Store chilled; flower hairs can irritate — strain thoroughly.

    Not a substitute for medical respiratory care.

    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

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.