Asclepias syriaca

Common milkweed

Caution

Other names: Common milkweed, Silkweed

Common milkweed—waste margins; monarch ecology and latex in folk use.

Perennial with opposite leaves and pinkish umbels.

Family: Brassicaceae
Plant type: Perennial herb

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.

Common milkweed — plant habitus (Wikimedia Commons). — Photograph on Wikimedia Commons (GFDL 1.2).
Plant habit

Safety — read before use

For this herb it is important to check warnings, mix-ups and cautions. Start with the Safety section.

Quick overview

A practical summary; details are in the sections below.

Safety grade: Caution details
Scientific sources on the card: No published records yet
When and what to harvest: Leaf — May–June
Fruit — July–August
Full harvest section
Processing methods: Culinary use, Poultice / compress
All methods and recipes on the card
Topics and symptoms: Skin
Topics section, Symptoms overview

Identification and mix-ups

Lyrate leaves and hollow erect stem.

Possible mix-ups and risks

Other milkweeds by flower and fruit.

Similar herbs

No related herbs are linked yet.

Topics and symptoms

More topics are in the symptoms and topics overview.

Skin
Traditional· Traditional / cultural framing

Geographic occurrence

Canada
Common (expected wild occurrence in the region)

Harvest

LeafMay–June
jaro
Region: Canada
Notes: Young shoots under 20 cm are snapped in May and June; pick only where the plant is abundant and leave most stems to the monarch butterflies, for which it is the sole host plant. Identify with certainty — the similar dogbane (Apocynum) is bitter and more poisonous.
FruitJuly–August
léto
Region: Canada
Notes: Young soft pods up to 3–4 cm are picked in July and August while the inside is white and the floss has not browned; older pods are tough and inedible.

Storage

Refrigeration(Leaf)
Shoots and pods keep 2–3 days in the fridge; process fresh, they can be frozen once cooked.
Moisture:
They wilt.
Safety:
Never raw; the milky sap irritates eyes and skin.

Processing methods on this herb card

Culinary use(Leaf)Suitability: Medium suitability
Cooking, baking, seasoning as food — general category without therapeutic claims.
Full method description (from the catalogue)
Culinary use covers herbs as ingredients in dishes, drinks, or spice mixes. This overview does not evaluate medicinal effects — only reminds you about species intent, allergies, and heat treatment where needed (e.g. some fruits or plant parts).
Combining with alcohol, sugar, or long cooking changes outcomes; verify culinary sources.
Traditional context for this method: yes·Scientific context for this method: no
Only young parts, only after boiling in changed water, only with certain identification. Not a vegetable for beginners.
Young milkweed shoots boiled in several waters
About 25 minAdvancedScience profile
Open recipe →
Poultice / compress(Leaf)Suitability: Low suitability
Liquid or paste on the skin, often through a thin cloth.
Full method description (from the catalogue)
A compress applies moist warm or cool material to the skin directly or through fabric. Duration and temperature are key — too hot can burn; too long can macerate the skin.
Use clean textiles and watch skin reaction during the first minutes.
Traditional context for this method: yes·Scientific context for this method: no
Folk use of the latex on warts — spot application only, not near eyes, not on broken skin.

Traditional / spiritual use

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

Plant of monarchs, prairie kitchens and life jackets
General
Traditional useFolk remediesFolk useHerbal lore
For the Prairie and Eastern Woodland peoples milkweed was a spring vegetable — shoots, buds and pods were boiled and the flowers cooked into syrup; in folk medicine the latex went on warts. During the Second World War American children collected tons of the silky seed floss as a kapok substitute for life jackets. Today milkweed is best known as the sole host plant of the monarch butterfly. A record of cultural tradition.
Form:
divoká zelenina, latex na bradavice, chmýří do záchranných vest
Claim strength:
Tradition
Source note:
Gonella & Kindscher 2024, Ethnobiology Letters; history of the US floss collection drive 1944–45.

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.

No published study records yet.

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.

Cardenolides — poisonous rawHigh severityToxins and regulation
Milkweed contains cardenolides (cardiac glycosides) and an irritant latex; raw or in quantity it acts on the heart and gut and is known for poisoning livestock. Indigenous peoples ate it only young and after boiling in changed water (Gonella & Kindscher 2024). Risk of confusion with dogbane (Apocynum), which is more poisonous — do not pick without certain identification.
Source