En EspaŃol
Share

NPIN: Native Plant Database

Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

Search native plant database:
Name:    
Family:    
See a list of all Plants





Asclepias syriaca (Common milkweed)
Cressler, Alan

Asclepias syriaca

Asclepias syriaca L.

Common milkweed

Asclepiadaceae (Milkweed Family)

Synonym(s): Asclepias intermedia, Asclepias kansana, Asclepias syriaca var. kansana

USDA Symbol: assy

USDA Native Status: L48 (N), CAN (N)

The Common Milkweed is the plant that most people associate with the word “milkweed”. This is a tall and conspicuous species that sometimes forms large clones. The umbels bear large balls of pink to purplish flowers that have an attractive odor. This species is known to form hybrids with both A. exaltata (in the east) and A. speciosa (in the west). The seed pods open in the fall and early winter dispensing wind borne seeds. Among the milkweeds, this species is the best at colonizing in disturbed sites. Within its range it can be found in a broad array of habitats from croplands, to pastures, roadsides, ditches and old fields. It is surprisingly rare in prairies in the Midwest being found mostly in disturbed sites within these habitats. As an indigenous species of the southern Great Plains, it has all the attributes of what some ecologists call a “fugitive species”. That is, one whose appearance and persistence is dependent on disturbance due to its inability to compete with other vegetation. In the northern parts of its range it seems to be a more permanent member of the floral communities.

This plant differs from Showy Milkweed (A. speciosa) in having an unbranched stem. The plant contains cardiac glycosides, allied to digitalins used in treating some heart disease. These glycosides, when absorbed by monarch butterfly larvae whose sole source of food is milkweed foliage, make the larvae and adult butterflies toxic to birds and other predators.

 

Plant Characteristics

Duration: Perennial
Habit: Herb
Leaf Arrangement: Opposite
Leaf Shape: Elliptic , Lanceolate , Oblong , Ovate
Inflorescence: Umbel
Fruit Type: Legume
Size Notes: Typically 3-5 feet (90-150 cm) but can reach 8 feet (240 cm) in ditches and gardens.
Leaf: 4-7 ˝ in (10-19 cm) long and 2-4 1/3 in (5-11 cm) wide. Shape is variable and is described as ovate, oblong, lanceolate or elliptic. The rich dark green of the top of the leaves contrasts with a lighter green on the underside. Leaf pairs often perpendicular to each other with short petioles.
Flower: Slightly pendulous spherical umbels with as many as 100 flowers per umbel, but usually 30+/- flowers. 3+/- umbels per stem. Pedicels are 1 1/2 in (4 cm) long. Petals up to 1/3 in (9mm) long. Hoods and horns are white or purple. Corolla reflexes backward to expose the hoods and horns. Horn protrudes through the hoods.
Fruit: Pods approximately 3 ˝ in (9 cm) long to 1 2/3 in (4 cm) at the widest point. Pod color is grayish and is thick at the base and tapers down to a narrow tip. Pods are covered with hair and soft spikes. Pods split open between September-October.
Size Class: 3-6 ft.

Bloom Information

Bloom Color: White , Purple
Bloom Time: Jun , Jul , Aug

Distribution

USA: AL , AR , CT , DC , DE , GA , IA , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MS , MT , NC , ND , NE , NH , NJ , NY , OH , OK , OR , PA , RI , SC , SD , TN , TX , VA , VT , WI , WV
Canada: MB , NB , NL , NS , ON , QC , SK
Native Distribution: Saskatchewan to New Brunswick; south to Georgia; west through Tennessee to Kansas and Iowa.
Native Habitat: Old fields, roadsides, and waste places.

Growing Conditions

Light Requirement: Sun
Soil Moisture: Moist
Soil Description: Medium to fine sandy, clayey, or rocky calcareous soils. Also found in well-drained loamy soils.
Conditions Comments: Not shade tolerant. Needs lots of sunlight.

Benefit

Use Food: According to the Field Guide to Medicinal Wild Plants or Edible Wild Plants, common milkweed is edible only under certain circumstances. Boiling can eliminate the bitter taste and toxicity of the sap, but this must be done very carefully to avoid the toxins. Eating milkweed is not recommended.
Use Other: Native Americans used this species as a source of fibers and during the Second World War children in the northern states were encouraged to collect the seed pods that were processed for the coma, or floss, which was used for floatation in life vests. Today the coma is harvested for use in pillows and comforters.
Warning: Poisonous parts include milky sap from leaves, stems. Toxic only in large quantities. Symptoms include vomiting, stupor, weakness, spasms by ingesting other species; need careful identification. Toxic Principle: Resinoid, cardiac glycoside in other species (Poisonous Plants of N.C. State).
Conspicuous Flowers: yes
Fragrant Flowers: yes
Attracts: Butterflies
Larval Host: Monarch
Poisonous: yes

Value to Beneficial Insects

Special Value to Native Bees
Special Value to Bumble Bees
Special Value to Honey Bees
Supports Conservation Biological Control

This information was provided by the Pollinator Program at The Xerces Society for Invertebrate Conservation.

Butterflies and Moths of North America (BAMONA)

Asclepias syriaca is a larval host and/or nectar source for:
Monarch
(Danaus plexippus)

Larval Host
Learn more at BAMONA

Propagation

Propagation Material: Seeds
Description: Spreads via rhizomes and forms small to large clones. Rhizomes can be cut and transplanted early in the spring.

Find Seed or Plants

Order seed of this species from Native American Seed and help support the Wildflower Center.

Find seed sources for this species at the Native Seed Network.

View propagation protocol from Native Plants Network.

Mr. Smarty Plants says

Native plants of dune erosion control in Michigan
May 30, 2008
We care for Lake Michigan dune near our home in New Buffalo and would like to provide erosion control with native species that will also enhance the beauty of the dune with long lasting flowers. The ...
view the full question and answer

National Wetland Indicator Status

Region:AGCPAKAWCBEMPGPHIMWNCNEWMVE
Status: UPL FACU FACU UPL FACU UPL FACU
This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

From the National Suppliers Directory

According to the inventory provided by Associate Suppliers, this plant is available at the following locations:

Edge of the Woods Native Plant Nursery - Orefield, PA
Sunshine Farm & Gardens - Renick, WV
Ohio Prairie Nursery - Hiram, OH
American Native Nursery - Quakertown, PA
Toadshade Wildflower Farm - Frenchtown, NJ

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is on display at the following locations:

Texas Discovery Gardens - Dallas, TX
Natural Biodiversity - Johnstown, PA
Native Seed Network - Corvallis, OR
* Available Online from Wildflower Center Store

Bibliography

Bibref 1186 - Field Guide to Moths of Eastern North America (2005) Covell, C.V., Jr.
Bibref 1185 - Field Guide to Western Butterflies (Peterson Field Guides) (1999) Opler, P.A. and A.B. Wright
Bibref 946 - Gardening with Prairie Plants: How to Create Beautiful Native Landscapes (2002) Wasowski, Sally
* The Midwestern Native Garden: Native Alternatives to Nonnative Flowers and Plants An Illustrated Guide (2011) Adelman, Charlotte and Schwartz, Bernard L.

Search More Titles in Bibliography

Web Reference

Additional resources

USDA: Find Asclepias syriaca in USDA Plants
FNA: Find Asclepias syriaca in the Flora of North America (if available)
Google: Search Google for Asclepias syriaca

Metadata

Record Modified: 2014-11-12
Research By: TWC Staff

Go back

E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center