Species · GBIF taxon 3170247
Asclepias syriaca
asclepias syriacaAlso known as Butterfly Flower, Silkweed, Silky Swallow-Wort, Virginia Silkweed
Common milkweed is a robust perennial wildflower famous for its sticky, milky latex sap and fragrant, spherical clusters of pinkish-purple blossoms. These plants serve as the primary nursery and food source for monarch butterfly caterpillars, which sequester the plant's toxic cardenolides for their own defense. In autumn, the large, bumpy seed pods split open to release hundreds of seeds, each equipped with silky white hairs designed to catch the wind.
PerennialHost PlantWildflower
—observations
—countries
—peak records
Least ConcernConservation statusIUCN Red List categoriesLCNTVUENCREWEXLeast ConcernRed List categories, explained →
Diet & prey
- Autotrophic (Photosynthetic)
Predators
- Monarch Butterfly Caterpillars
- Milkweed Tussock Moth Caterpillars
- Large Milkweed Bugs
ThreatsHabitat loss, herbicide use, and mowing of roadside corridors
HabitatsFields, roadsides, prairies, pastures, and sunny gardens with well-drained soils
Life spanPerennial (individual stems live one season, root system can persist for decades)
Size / weightNot available
Classification
- OrderGentianales
- FamilyApocynaceae
- GenusAsclepias
- Speciesasclepias syriaca
Range data is not available yet.
Interaction riskHigh
- Low
- Moderate
- High
- Very high
- Why interaction risk is high
- All parts contain toxic cardiac glycosides; do not ingest and wash hands after handling the milky sap.
- Why it is dangerous
- Contains toxic cardiac glycosides that can cause nausea, vomiting, and heart rhythm issues if ingested, and the milky sap is a skin and eye irritant.
- How to recognize a risky encounter
- Look for thick, opposite leaves, spherical clusters of pink-purple flowers, and sticky white sap when a leaf is torn.
- What to do
- Wash hands thoroughly after touching the plant, and never allow the white sap to contact your eyes or mouth.
- What to notice
- Recognizable by its broad, velvety leaves and large, bumpy green seed pods in late summer.
- Support conservation
- Avoid mowing or clearing milkweed patches during the spring and summer breeding seasons.
Responsible observation
- Observe Monarchs: Look closely at the undersides of leaves for tiny, ribbed monarch eggs or striped caterpillars.
- Avoid Sap Contact: Do not touch your eyes or face after snapping a leaf, as the milky latex is highly irritating.
- Smell the Blooms: Gently sniff the dome-like flower clusters in midsummer to enjoy their intense, sweet fragrance.
Symbiont Sid Mosdell from New Zealand / CC BY 2.0 · cc-by
Herbivore (c) Katja Schulz, some rights reserved (CC BY) · cc-by
Close Relative (c) Michael J. Papay, some rights reserved (CC BY), uploaded by Michael J. Papay · cc-by
Close Relative (c) aarongunnar, some rights reserved (CC BY), uploaded by aarongunnar · cc-by
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