General: Milkweed Family (Asclepiadaceae). Common milkweed (Asclepias syriaca) is a perennial herb growing from a deep rhizome. The hairy stems are usually solitary from a simple to branched and thickened base, and are 6-20 dm (1.9-6.5 ft) tall. The opposite leaves have broadly ovate to elliptic blades that are 10-20 cm (3.9-7.9 in) long and 5-11 cm (1.9-4.3 in) wide. The leaves are sparsely hairy above and densely hairy below, and the petiole is 0.2-1.4 cm (0.08-0.77 in) long. The inflorescence occurs in the upper leaf axils, and there are 20-130 flowers per inflorescence. The flowers are small, 11-17 mm (0.4-0.7 in), and bloom from May to August. The five petals are green to purple-tinged, and are topped by a crown of five erect lobes that are rose to purple, rarely white. The fruits are spindle-shaped follicles covered with soft hairs. The small, round, hairy seeds are 6-8 mm (0.2-0.3 in) in diameter.
Distribution: For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. This plant grows throughout the Great Plains ecoregion from southern Canada south to NE Oklahoma, NW Georgia, and Texas, and east from North Carolina to Maine.
Virginia-silk, algodoncillo, silky swallowwort, herbe à la ouate, Seidenpflanze
Range and Habitat in Illinois
Regularity: Regularly occurring
Regularity: Regularly occurring
Range and Habitat in Illinois
Adaptation: Common milkweed grows in sandy, clayey, or rocky calcareous soils. It occurs along the banks or flood plains of lakes, ponds, and waterways, in prairies, forest margins, roadsides, and waste places. This species hybridizes with showy milkweed (Asclepias speciosa).
Common milkweed is easily propagated by both seed and rhizome cuttings. Both seedlings and cuttings will usually bloom in their second year, although cuttings will occasionally bloom during their first year. Seeds and plants are available from many nurseries. Common milkweed increases by underground shoots and can be invasive. It is ideal in semi-dry places where it can spread without presenting problems for other ornamental species.
Propagation from Cuttings: Propagation by cuttings of the tuberous rhizome is easy and reliable. The cuttings should be made when the plant is dormant. Each piece of the rhizome should have at least one bud (they are about two inches apart). Timing of propagation is important. Harvest or divide plants and get the plants in the ground by late fall so they can develop enough root growth to survive the winter. Irrigation the first year will improve survival, and by the second year the root system should be well enough established so plants will survive on their own.
Both seedlings and cuttings will usually bloom in their second year, although cuttings will occasionally bloom during their first year (Kindscher 1992).
Propagation from Seed: Common milkweed is easily propagated from seed. Process as follows:
1) Collect seeds after the pods have ripened, but before they have split open. The seeds are wind dispersed, so be careful when gathering to place in a paper or burlap bag to avoid losing them.
2) Eliminate weeds before planting. Strip off any sod. Cultivate the soil to a fine tilth, firm the soil by treading or rolling, and rake lightly.
3) Seeds can be directly sewn into the ground in the fall. Sow the seed mixture (with fine sand for even distribution) at a rate of 1/8 oz per sq. yd (4 g per sq. meter) or as advised.
4) If planting in flats or in a greenhouse, common milkweed seeds should be cold-treated for three months.
5) The seed is very viable. It is not certain how long you can store the seeds and maintain their viability.
6) During the first summer, weed invasive plants and water as needed.
Flower-Visiting Insects of Common Milkweed in Illinois
(Insects suck nectar; most observations are from Robertson, although some observations are from Moure & Hurd, Betz, Krombein et al., Hilty, and Swengel & Swengel as indicated below)
Apidae (Bombini): Bombus griseocallis; Anthophoridae (Anthophorini): Anthophora abrupta; Anthophoridae (Epeolini): Epeolus bifasciatus, Triepeolus remigatus; Anthophoridae (Eucerini): Florilegus condigna, Melissodes agilis, Melissodes comptoides, Melissodes tepaneca, Peponapis pruinosa pruinosa fq, Synhalonia rosae, Synahalonia speciosa, Xenoglossa strenua; Megachilidae (Coelioxini): Coelioxys octodentata; Megachilidae (Megachilini): Megachile petulans, Megachile texana
Halictidae (Halictinae): Agapostemon sericea, Halictus confusus, Halictus rubicunda; Halictidae (Sphecodini): Sphecodes ranunculi; Colletidae (Colletinae): Colletes latitarsis, Colletes nudus
Sphecidae (Bembicinae): Bembix nubilipennis, Stictia carolina; Sphecidae (Larrinae): Tachytes aurulenta; Sphecidae (Philanthinae): Cerceris bicornuta; Sphecidae (Sphecinae): Prionyx atrata fq, Prionyx thomae, Sphex ichneumonea; Vespidae (Eumeninae): Euodynerus annulatus; Tiphiidae: Myzinum quinquecincta; Scoliidae: Campsomeris plumipes, Scolia bicincta
Mydidae: Mydas clavatus; Syrphidae: Eristalis dimidiatus, Mallota albipilis, Mallota bautias, Syritta pipiens, Tropidia mamillata, Tropidia quadrata; Conopidae: Physocephala texana; Tachinidae: Archytas analis, Belvosia bifasciata, Belvosia unifasciata, Linnaemya comta, Trichopoda plumipes; Muscidae: Helina rufitibia
Nymphalidae: Danaus plexippus, Nymphalis antiopa, Polygonia interrogationis, Speyeria cybele, Vanessa atalanta
Hesperiidae: Achalarus lyciades
Sphingidae: Xylophanes tersa; Ctenuchidae: Cisseps fulvicollis
Lampyridae: Photinus pyralis
Lygaeidae: Lygaeus turcicus, Oncopeltus fasciatus; Pentatomidae: Euschistus variolaria, Podisus maculiventris prd
Apidae (Bombini): Bombus auricomus, Bombus pensylvanica fq; Anthophoridae (Eucerini): Svastra obliqua obliqua; Megachilidae (Megachilini): Megachile brevis brevis
Halictidae (Halictinae): Augochloropsis metallica metallica
Sphecidae (Philanthinae): Cerceris clypeata; Sphecidae (Sphecinae): Sceliphron caementaria
Culicidae: Aedes stimulans; Stratiomyidae: Odontomyia cincta; Bombyliidae: Anthrax sinuosa; Conopidae: Stylogaster biannulata; Tachinidae: Gymnoclytia occidua
Nymphalidae: Limenitis archippus, Speyeria idalia; Lycaenidae: Lycaena hyllus, Satyrium calanus; Pieridae: Colias philodice; Papilionidae: Battus philenor
Hesperiidae: Epargyreus clarus, Pholisora catullus, Polites peckius, Polites themistocles
Pollinia Presence Unspecified:
Apidae (Apinae): Apis melliera (Btz) fq; Apidae (Bombinae): Bombus pensylvanica (Btz); Megachilidae (Trypetini): Heriades carinatum (Kr)
Halictidae (Halictinae): Augochlorella striata (MH)
Sphecidae (Sphecinae): Sphex ichneumonea (Btz)
Lycaenidae: Lycaeides melissa samuelis (Sw)
Sesiidae: Melittia cucurbitae (H)
Found dead or entrapped on flowers:
Apidae (Apinae): Apis mellifera
Tachinidae: Spallanzania hesperidarum; Sarcophagidae: Ravinia anxia; Muscidae: Neomyia cornicina, Stomoxys calcitrans
Arctiidae: Haploa colona; Noctuidae: Agrotis ipsilon, Caenurgina erechtea
Molecular Biology and Genetics
Statistics of barcoding coverage: Asclepias syriaca
Public Records: 4
Specimens with Barcodes: 12
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status and wetland indicator values.
- Aeschimann, D. & C. Heitz. 2005. Synonymie-Index der Schweizer Flora und der angrenzenden Gebiete (SISF). 2te Auflage. Documenta Floristicae Helvetiae N° 2. Genève. http://www.crsf.ch/
Cultivars, improved and selected materials (and area of origin)
ASSY is readily available through native plant nurseries within its range.
Milkweed is burned in the fall to eliminate dead stalks and stimulate new growth. Burning causes new growth to have taller, straighter stems (with longer fibers). It also stimulates flower and seed production.
When used for fiber, milkweed is collected in the autumn after the leaves have begun to fall off, the stalks turn gray or tan, and the plant dries up. If the milkweed stems will break off at the ground it's time to harvest. Breaking off as many stalks as possible encourages resprouting in the spring. The dried stalks are then split open and the fibers are twisted into string. Vast quantities of fiber plants are required for nets, regalia, and cordage.
Relevance to Humans and Ecosystems
Warning: Milkweed may be toxic when taken internally, without sufficient preparation.
Ethnobotanic: People have used milkweed for fiber, food, and medicine all over the United States and southern Canada. Milkweeds supply tough fibers for making cords and ropes, and for weaving a coarse cloth. Milkweed stems are collected after the stalks senesce in late fall-early winter. The dried stalks are split open to release the fibers; milkweed fibers are sometimes mixed with fibers of Indian hemp (Apocynum cannabinum). The bark is removed and the fibers released by first rubbing between the hands and then drawing the fibers over a hard surface. Twisting the fiber opposite each other and twining them together forms the cord. Often this is accomplished by rolling the fibers on the thigh while twisting them together.
The young shoots, stems, flower buds, immature fruits, and roots of butterfly milkweed were boiled and eaten as a vegetable by various indigenous groups of eastern and mid-western America. The Meskwaki steam the flower buds as a food source; they are nutritious but not considered very flavorful.
The Cherokee drank an infusion of common milkweed root and virgin’s bower (Clematis species) for backaches (Moerman 1986). The Cherokee, Iroquois, and Rappahannock used the sap to remove warts, for ringworm, and for bee stings. The Cherokee used the plant as a laxative, an antidote for gravel and dropsy, and an infusion was given for mastitis. The Cherokee took an infusion of the root for venereal diseases. The Chippewa made a cold decoction of common milkweed root and added it to food to produce postpartum milk flow. The Iroquois took an infusion of milkweed leaves for stomach medicine. A compound decoction of plants was taken to prevent hemorrhage after childbirth by the Iroquois. The Menominee ate the buds or a decoction of the root for chest discomfort. The Ojibwa used the root as a female remedy. The Potawatomi used the root for unspecified ailments.
Common milkweed was used by the Meskwaki as a contraceptive (Kindscher 1992, Erichsen-Brown 1979, De Laszlo and Henshaw 1954). A Mohawk anti-fertility concoction was prepared by boiling a fistful of dried, pulverized milkweed and three jack-in-the-pulpit rhizomes in a pint of water for 20 minutes. The infusion was drunk at the rate of one cup an hour to induce temporary sterility (Kindscher 1992).
Milkweed species as a group are known to contain cardiac glycosides that are poisonous to humans and livestock, as well as other substances that may account for their medicinal effect. Resinoids, glycosides, and a small amount of alkaloids are present in all parts of the plant. Symptoms of poisoning by the cardiac glycosides include dullness, weakness, bloating, inability to stand or walk, high body temperature, rapid and weak pulse, difficulty breathing, dilated pupils, spasms, and coma.
Wildlife: The cardiac glycoside in milkweed has also been useful as a chemical defense for monarch butterflies (Danaus plexippus). Chemicals from the milkweed plant make the monarch caterpillar's flesh distasteful to most predators. Monarch butterflies are specific to milkweed plants; this is the only type of plant on which the eggs are laid and the larvae will feed and matures into a chrysalis. Eggs are laid on the underside of young, healthy leaves. Monarch, Queen, and Viceroy butterflies are Müllerian mimics; all are toxic, and have co-evolved similar warning patterns to avoid predation. Milkweed species are attractive to many insect species, including the large milkweed bug, common milkweed bug, red milkweed beetle, blue milkweed beetle, and bees. Accordingly, this is a wonderful horticultural plant for landscaping to attract butterflies (particularly monarchs), whose numbers are declining and migratory routes changing due to lack of appropriate habitat.
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Asclepias syriaca, commonly called common milkweed, butterfly flower, silkweed, silky swallow-wort, and Virginia silkweed, is a species of flowering plant. It is in the genus Asclepias, the milkweeds. This species is native to Southern Canada and of much of the conterminous Eastern U.S., east of the Rocky Mountains, excluding the drier parts of the Prairies. It grows in sandy soils and other kinds of soils in sunny areas. It was one of the earliest North American species described in Cornut's 1635 work Canadensium Plantarum Historia. The specific name was reused by Linnaeus due to Cornut's confusion with a species from Asia Minor.
Common milkweed is a perennial herb growing up to 2.6 m tall from a rhizome. The all parts of common milkweed plants produce white latex when broken. The leaves are opposite or sometimes whorled; simple, broad ovate-lanceolate; up to 25 cm long and 12 cm broad, usually with undulate margins and reddish main veins. They have very short petioles and velvety undersides.
The fragrant, nectariferous flowers occur in umbellate cymes. Individual flowers are about 1 cm in diameter, each with five cornate hoods and five pollinia. The seeds, each with long, white flossy hairs, occur in large follicles.
The plant's latex contains large quantities of glycosides, making the leaves and seed pods toxic to sheep and other large mammals, and potentially humans (though large quantities of the foul-tasting parts would need to be eaten). The young shoots, young leaves, flower buds and immature fruits are all edible raw.
Concerns about milkweed bitterness and toxicity can be traced back to Euell Gibbons, author of Stalking the Wild Asparagus (1962). It is theorized that Gibbons inadvertently prepared dogbane (Apocynum cannabinum), a poisonous look-alike instead. He devised a method to remove the bitterness and toxicity by plunging the young shoots into boiling water (not cold) and cooking for one minute, repeating the procedure at least three times to make the plant safe to eat. Gibbons' method was copied from book to book, dominating edible plants literature for forty years. Most modern foragers consider the bitterness/toxicity issue a myth. The plants have no bitterness when tasted raw, and can be cooked like asparagus, with no special processing.
Failed attempts have been made to exploit rubber (from the latex) and fiber (from the seed's floss) production from the plant industrially. The fluffy seed hairs have been used as the traditional background for mounted butterflies. The compressed floss has a beautiful silk-like sheen. The plant has also been explored for commercial use of its bast (inner bark) fiber which is both strong and soft. U. S. Department of Agriculture studies in the 1890s and 1940s found that Milkweed has more potential for commercial processing than any other indigenous bast fiber plant, with estimated yields as high as hemp and quality as good as flax. Both the bast fiber and the floss were used historically by Native Americans for cordage and textiles. Milkweed oil from the seeds can be easily converted into cinnamic acid, which is a very potent sunscreen when used at a 1-5% concentration.
Many insects live on the plant, including the red milkweed beetle (Tetraopes tetrophtalmus), the large milkweed bug (Oncopeltus fasciatus), the small milkweed bug (Lygaeus kalmii), the milkweed leaf beetle (Labidomera clivicollis), the weevil species Rhyssomatus lineaticollis, and the Monarch butterfly (Danaus plexippus). The larva of the Monarch butterfly specializes on milkweeds, and its populations fall when milkweeds are eliminated with pesticides.
Deforestation due to European settlement may have expanded the range and density of milkweed. The plant can become invasive; it is naturalized in several areas outside of its native range, including Oregon and parts of Europe.
- Asclepias syriaca. USDA Natural Resources Conservation Service.
- Lamoureux, G., et al. (1978). Plantes sauvages des villes et des champs. Fleurbec/Éditeur officiel du Québec. ISBN 2-920174-00-2.
- Lamoureux, G., et al. (1981). Plantes sauvages comestibles. Fleurbec. ISBN 2-920174-03-7.
- Brother Marie-Victorin (1975). Flore Laurentienne. Les Presses de l'Université de Montréal. ISBN 0-8405-0018-1.
- Buchanan, R. (1987). A Weaver's Garden. Interweave Press, Inc. ISBN 0-934026-28-9.
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