General: Milkweed Family (Asclepiadaceae). Asclepias tuberosa is a perennial herb 3-9 dm tall with woody rootstocks. According to Kelly Kindscher (1992), "Asclepias comes from the name of the Greek god of medicine, Asklepios. The species name, tuberosa, means full of swellings or knobs, referring to the enlarged root system." Butterfly milkweed stems are hairy, erect, and grow in numerous clumps. There is a watery sap within the stems and leaves. The leaves are alternate, simple, crowded, lance-shaped, 5-10 cm long, shiny green, smooth above and velvety beneath. The flowers are in showy, rounded to flat-topped groups near the ends of branches. Each flower has 5 petals, bent downward, orange to red or sometimes yellow, topped by a crown of 5 erect hoods, each one containing a short horn. Fruits are hairy, spindle-shaped pods 8-15 cm long. The numerous seeds each have a tuft of long white hairs at the tip.
orange milkweed, chigger weed
Range and Habitat in Illinois
Regularity: Regularly occurring
Regularity: Regularly occurring
Global Range: A. tuberosa occurs in southeastern Canada, south through all states in the eastern half of the continental United States (except North Dakota), and southwestwards into Utah, California, and northern Mexico (USDA-NRCS 1999, Cronquist et al. 1984). This species is known from only one site in Maine, where it has since been extirpated (Maine Natural Areas Program).
Milkweeds grow in clumps beside roadways, on abandoned farmlands, and in other open areas throughout the United States. Butterfly milkweed grows on sandy, loamy, or rocky limestone soils of prairies, open woodlands, roadsides, and disturbed areas similar to other milkweed species. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.
Range and Habitat in Illinois
Comments: The habitats of A. tuberosa seem to shift in going from east to west. From the tallgrass prairie ecoregion and eastwards, A. tuberosa occurs in prairies and dry woods or savannas, especially in sandy soils (Gleason and Cronquist 1963, Swink and Wilhelm 1994). In the Great Plains region, the habitat is described as roadsides and waste places (Great Plains Flora Association 1986). In the Rocky Mountain vicinity, the regional habitats described are near springs (in western Colorado) (Weber and Wittmann 1996a); in moist to somewhat moist, sandy (or sometimes gravelly) soils "in open ponderosa pine, oak, and pinyon-juniper communities," between elevations of 1300m and 2400m (in Utah and Arizona) (Cronquist et al. 1984); and in sage and mountain brush communities (in Utah) (Welsh et al. 1993).
Butterfly 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 of selected cultivars are available from many nurseries. When the roots of the butterfly milkweed were more commonly harvested for their medicinal use, the plants were dug when dormant in the late fall. Butterfly 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.
Flower-Visiting Insects and Hummingbirds of Butterfly Milkweed in Illinois
(Insects & hummingbirds suck nectar; observations are from Hilty, Betz, Evans, Petersen, Moure & Hurd, LaBerge, Herms, Grundel & Pavlovic, MacRae, and Swengle & Swengel as indicated below, otherwise they are from Robertson)
Apidae (Apinae): Apis mellifera fq; Anthophoridae (Eucerini): Melissodes communis, Melissodes tepaneca; Megachilidae (Anthidinini): Anthidium maculifrons; Megachilidae (Coelioxini): Coelioxys octodentata
Halictidae (Halictinae): Augochloropsis metallica metallica
Sphecidae (Sphecinae): Ammophila nigricans, Ammophila procera, Prionyx thomae, Sphex ichneumonea
Tachinidae: Spallanzania hesperidarum
Nymphalidae: Speyeria cybele, Speyeria idalia; Pieridae: Colias philodice; Papilionidae: Battus philenor, Papilio polyxenes asterias, Papilio troilus
Ctenuchidae: Cisseps fulvicollis
Megachilidae (Megachilini): Megachile brevis brevis fq, Megachile montivaga
Sphecidae (Sphecinae): Prionyx atrata
Nymphalidae: Danaus plexippus, Phyciodes tharos; Lycaenidae: Everes comyntas, Lycaena hyllus, Satyrium titus; Papilionidae: Papilio glaucus
Pollinia Presence Unspecified:
Trochilidae: Archilochus colubris (H)
Apidae (Apinae): Apis mellifera (Btz); Apidae (Bombini): Bombus pensylvanica (Btz) fq; Anthophoridae (Ceratinini): Ceratina dupla dupla (Ev); Anthophoridae (Eucerini): Melissodes agilis (Pt), Melissodes bimaculata bimaculata (LB); Megachilidae (Megachilini): Megachile brevis brevis (Btz), Megachile latimanus (Ev), Megachile mendica (Ev); Megachilidae (Trypetini): Heriades carinatum (Ev)
Halictidae (Halictinae): Augochlorella persimilis (MH), Augochlorella striata (MH), Augochloropsis metallica metallica (Ev), Halictus confusus (Ev), Halictus rubicunda (Ev), Lasioglossum pectoralis (Ev), Lasioglossum pilosus pilosus (Ev); Colletidae (Colletinae): Colletes simulans armatus (Btz); Colletidae (Hylaeinae): Hylaeus affinis (Ev)
Sphecidae (Sphecinae): Sphex ichneumonea (Btz)
Nymphalidae: Danaus plexippus (Btz, H); Lycaenidae: Lycaeides melissa samuelis fq (GP, Hm, Sw), Satyrium titus (Btz); Papilionidae: Papilio polyxenes asterias (H)
Buprestidae: Acmaeodera pulchella (McR)
Lygaeidae: Lygaeus kalmii (Btz) fq
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
Comments: Many thousands of populations are extant rangewide. Nebraska: common, but rarer than formerly due to land use changes; Kansas: probably thousands of populations, scattered in tallgrass and mixed-grass prairies across the eastern two-thirds of the state; Missouri: common; Arkansas: reported from almost every county; Georgia: very common; Mississippi: occurs commonly over a large area, 47 counties; New York: probably about 100 populations; Vermont: known only from several collections from the late 1800's and early 1900's, all made within two counties; Indiana: common, occurs throughout the state, especially in the northern portion; Illinois: very common, frequently encountered in prairie areas, especially in sand prairies; Michigan: relatively common throughout southern Lower Michigan, ranges through northern Lower Michigan, frequent in prairies, old fields, prairie remnants, roadsides, along railroads, etc.; Ontario: about 100 populations; Kentucky: infrequent but not tracked; Texas: common, not tracked; New Hampshire: listed endangered, known only from seven historical occurrences (Natural Heritage Programs).
Molecular Biology and Genetics
Barcode data: Asclepias tuberosa
Statistics of barcoding coverage: Asclepias tuberosa
Public Records: 3
Specimens with Barcodes: 11
Species With Barcodes: 1
Statistics of barcoding coverage: Asclepias tuberosa L.
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Although this species remains very common in parts of its range, it appears to be in severe decline in others. Habitat destruction and manipulation has caused a range wide decline of this species. The general center of this species distribution (the eastern tallgrass prairie states) has been almost entirely converted to agricultural and urban uses. Fragmentation of remaining habitat, contamination of the gene pool, and wild harvesting present ongoing threats to this species. Nevertheless, it is still quite common in semi-natural settings such as roadsides and old fields.
Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status, such as, state noxious status, and wetland indicator values.
Global Short Term Trend: Decline of 10-30%
Comments: Though information on most current trends may not be available, A. tuberosa has certainly declined in certain parts of its range within the last few hundred years. Many of the open woods of the east, and virtually all of the prairies in the Midwest, have been destroyed for agriculture and development within this time period. It is not as common in Nebraska as it used to be because of changes in land use (Nebraska Natural Heritage Program). In the early 1900's the roots of A. tuberosa were commercially available for medicinal purposes (Weiner 1980). Presumably, this material was collected from the wild.
Comments: There is some collecting in Missouri from roadsides for use in home landscaping, but no medicinal collecting (Tim Smith pers. comm.). It may be collected for use in prairie restoration, and for ornamental use (Mike Penskar pers. comm.). It is used ornamentally in gardens (Niering 1979). At least one wild population in Illinois has been damaged by direct collecting of whole plants. In other cases, where cultivated varieties don't represent local genotypes, there is a threat that genetic contamination of the wild populations is occurring, as the wild and cultivated populations intermix.
An individual familiar with the herbal medicinal commercial markets in the U.S. estimates that this plant receives minor to moderate usage which is not increasing, and states that the plant is not cultivated. It is the roots that are collected (McGuffin pers. comm.).
A. tuberosa may be poisonous to livestock (Great Plains Flora Association 1986). Though there are no known reports to this effect, it is possible that farmers andranchers try to diminish this species when it occurs on their land.
Many of the habitats reported for A. tuberosa are open or semi-open communities (prairies, fields, open woodlands, dry woods, savannas, barrens, shrublands, etc.). In recent years there has been an increasing awareness of the role of fires in maintaining such communities, and in the increasingly poor condition of these communities after decades of lowered fire frequency. In the Great Lakes region, for example, many oak-dominated barrens on sandy soils have reverted to structurally forested or thickety habitats in the absence of fire, and this is detrimental to A. tuberosa. Furthermore, many native prairie relicts within the range of A. tuberosa are legally protected but are suffering from lack of adequate management attention. In such cases the survival of A. tuberosa is probably not certain (though some regional floras describe A. tuberosa as somewhat weedy, and thus possibly tolerant of natural community deterioration, others do not (Swink and Wilhelm 1994)).
In Nebraska, this species is threatened by cattle grazing, annual midsummer haying, pesticide application, plowing of prairie, and exotic plant invasions (Gerry Steinauer pers. comm.). In Ontario, it is reportedly threatened by loss of prairie and savanna habitats due to lack of fire, invasions by exotics, overgrazing by deer, and conversion of habitat for agricultural uses (Mike Oldham pers. comm.). The primary threats in Kansas are from urban and agricultural developments, and overgrazing (Craig Freeman pers. comm.).
This species is included on the United Plant Savers "To Watch List" (United Plant Savers 2000).
Biological Research Needs: A solid conservation assessment for A. tuberosa would need to include further information on: 1. the general intensity and extent of collecting from wild populations; 2. the extent to which it is associated with fire-dependent habitats towards the Appalachian and Atlantic regions; 3. the extent to which it is weedy, and can adapt to ruderal habitats in the Great Plains region; and 4. whether it is often exterminated by ranchers and farmers. Information in some regards may already exist but is unknown to the authors of this report.
Cultivars, improved and selected materials (and area of origin)
ASTU is readily available through native plant nurseries within its range. Seeds and plants of selected Asclepias cultivars are available from many nurseries. It is best to plant species from your local area, adapted to the specific site conditions where the plants are to be grown.
Both milkweed and dogbane are 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. Blackburn and Anderson (1993) quote Craig Bates of the Yosemite Museum that it takes approximately five stalks of milkweed or Indian hemp to manufacture one foot of cordage. A Sierra Miwok feather skirt or cape contained about 100 feet of cordage made from approximately 500 plant stalks, while a deer net 40 feet in length (Barrett and Gifford 1933:178) contained some 7,000 feet of cordage, which would have required the harvesting of a staggering 35,000 plant stalks.
Propagation by cuttings of the tuberous rhizome is also 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).
Asclepias tuberosa is easily propagated from seed. 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. Butterfly milkweed seeds should be cold-treated for three months. Seeds can be directly sewn into the ground in the fall. The seed is very viable. It is not certain how long you can store the seeds.
Relevance to Humans and Ecosystems
Uses: FOOD, MEDICINE/DRUG, FIBER
Production Methods: Cultivated, Wild-harvested
Comments: The roots of A. tuberosa were used extensively by Native American and Euro-Americans for medicines, especially for lung related ailments (Weiner 1980, Niering 1979). It is well-known for its medicinal uses and has been traded as a medicinal plant for at least 100 years; its use is as a pleurisy root for lung problems (Robyn Klein pers. comm.).
Warning: Milkweed may be toxic when taken internally, without sufficient preparation.
Ethnobotanic: Milkweed has been used for fiber, food, and medicine by people all over the United States and southern Canada. Fibers from the stems of milkweed have been identified in prehistoric textiles in the Pueblo region. Tewa-speaking people of the Rio Grande still make string and rope from these fibers. At the Zuni Pueblo, the silky seed fibers are spun on a hand-held wooden spindle and made into yarn and woven into fabric, especially for dancers. Pueblo people ate green milkweed pods and uncooked roots from one of the species that forms fleshy tubers underground.
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 to 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. The cord is
formed by twisting the fiber opposite each other and twining them together. 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.
Butterfly milkweed has many medicinal uses. The Omahas and Poncas ate the raw root of the butterfly milkweed for bronchial and pulmonary troubles. Butterfly milkweed root was also chewed and placed on wounds, or dried, pulverized, and blown into wounds. The Omaha tribe used butterfly milkweed medicine for rites belonging to the Shell Society. The Dakotas used the butterfly milkweed as an emetic. The Menominis considered the butterfly milkweed, which they called the "deceiver," one of their most important medicines.
Generalized medicinal uses for milkweed species include 1) its use in a salve for scrofulous swelling, 2) as a diarrhea medicine, 3) drunk by mothers unable to produce milk, 4) medicine for snow blindness and other forms of blindness, 5) relief of sore throat, 6) applied chewed root for swelling and rashes, 7) to expel tapeworm, 8) to treat colic, 9) to act as contraceptives, and 10) to cure snakebite.
European Americans used Asclepias tuberosa, called "pleurisy root", to relieve inflammation of the lining of the lungs and thorax, and to relieve bronchial and pulmonary trouble. Pleurisy root is a stimulant to the vagus nerve, producing perspiration, expectoration, and bronchial dilation. As its name signifies, it is useful for pleurisy and mild pulmonary edema, increasing fluid circulation, cilia function, and lymphatic drainage. The root of the butterfly milkweed, was officially listed in the U.S. Pharmacopoeia from 1820 to 1905 and in the National Formulary from 1916 to 1936.
Milkweed species, as a group, are known to contain cardiac glycosides that are poisonous both to humans and to 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.
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 mature 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.
Wildlife: 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. Butterfly milkweed also has strikingly beautiful flowers.
Caution: At one time, milkweed was classified as a noxious weed due to reported toxic effects on livestock, and efforts were made to eradicate it. Milkweeds are thought to be poisonous to cows and sheep. Milkweed also can have invasive characteristics in disturbed areas.
Asclepias tuberosa is a species of milkweed native to eastern North America. It is a perennial plant growing to 0.3–1 metre (1 ft 0 in–3 ft 3 in) tall, with clustered orange or yellow flowers from early summer to early fall. The leaves are spirally arranged, lanceolate, 5–12 cm long, and 2–3 cm broad.
This plant favors dry, sand or gravel soil, but has also been reported on stream margins. It requires full sun.
It is commonly known as Butterfly Weed because of the butterflies that are attracted to the plant by its color and its copious production of nectar. It is also the larval food plant of the Queen and Monarch butterflies. Hummingbirds, bees and other insects are also attracted.
Extracts were used by Native Americans as an expectorant for wet coughs and other pulmonary ailments. Use of the herb is contraindicated in pregnancy, during lactation or with infants due to the small amount of cardiac glycosides.
The plant looks similar to the Lanceolate Milkweed (Asclepias lanceolata), but is uniquely identified by the larger number of flowers, and the hairy stems that are not milky when broken. It is most commonly found in fields with dry soil.
Most easily propagated by seed. Sewn outdoors after frost, a plant will flower and produce seed in the third year. Difficult to transplant once established. Loewer, Peter 'Native Perennials For the Southeast' Cool Springs Press. Nashville, Tenn. 2005 ISBN 1-59186-121-7 
It does not spread easily.
- Asclepias tuberosa subsp. interior – (Central United States)
- Asclepias tuberosa subsp. rolfsii – Rolfs Milkweed (Southeastern United States)
- Asclepias tuberosa subsp. tuberosa – (Eastern United States)
Common names include Butterfly Weed, Canada Root, Chieger Flower, Chiggerflower, Fluxroot, Indian Paintbrush, Indian Posy, Orange Milkweed, Orange root, Orange Swallow-wort, Pleurisy Root, Silky Swallow-wort, Tuber Root, Yellow Milkweed, White-root, Windroot, Butterfly Love, Butterflyweed, and Butterfly Milkweed.
- "The Plant list: A Working List of All plant Species".
- Nina Cummings, ed. (2011). "Native Landscaping Takes Root in Chicago". In The Field (The Field Museum): 13.
- University of Texas, Austin
- personal gardening experience (mid-Atlantic, zone 7)
- Druse, Ken 'Making More Plants The Science, Art, and Joy of Propagation' Abrams. New York, NY. 2012 ISBN 0-517-70787-X
- http://www.ourhabitatgarden.org/creatures/milkweed-growing.html Our Habitat Garden .org
- "USDA GRIN Taxonomy".
- anonymous (2008). "Featured Native Plant: Butterfly Weed". Wild Ones: Native Plants, Natural Landscapes 6 (4).
- Dickinson, T.; Metsger, D.; Bull, J.; & Dickinson, R. (2004) ROM Field Guide to Wildflowers of Ontario. Toronto:Royal Ontario Museum, p. 138.
- Peterson, Roger Tory; Margaret McKenny (1968). A Field Guide to Wildflowers of Northeastern and North-central North America. Boston: Houghton Mifflin Company. ISBN 0-395-18325-1.
- Photo of a J.J. Audubon Plate Clay-Colored Sparrow perched atop Asclepias tuberosa
Names and Taxonomy
Comments: Three subspecies of Asclepias tuberosa are recognized by Kartesz (floristic synthesis, 1999): subsp. interior, comprising populations roughly from the Appalachian area and westwards; subsp. tuberosa, comprising populations east of the Plains states; and subsp. rolfsii, comprising populations in Florida and in adjoining states (Kartesz, 1999; USDA-NRCS 1999). The subspecific divisions are based mainly upon leaf shape, and are loosely separated along introgressive boundaries (Cronquist et al. 1984).
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