CPC National Collection Plant Profile

Asclepias meadii

Marlin Bowles

Heading for profile page
CPC Home Join now
About CPC
CPC National Collection
Conservation Directory Resources
Invasive Plant Species Plant News
Plant Links Participating Institutions
Search CPC
Search    Alphabetical List    Reference Finder    CPC Home

CPC National Collection Plant Profile

Asclepias meadii

Common Name: 
Mead's milkweed
Torr. ex Gray
Growth Habit: 
CPC Number: 


Profile Links
 Fish & WildLife
 Forest Service

Asclepias meadiienlarge
Photographer: Marlin Bowles

Asclepias meadiienlarge
Photographer: Marlin Bowles

Asclepias meadii is Fully Sponsored
Primary custodian for this plant in the CPC National Collection of Endangered Plants is: 
Marlin L. Bowles contributed to this Plant Profile.

Asclepias meadii

This rare, attractive species of Midwestern tallgrass prairies and glades. Today, all of the tallgrass prairie populations of this species in Wisconsin, Illinois, and Indiana have been destroyed by agriculture, and the only remaining native eastern populations occupy glade habitat in southeastern Missouri and southern Illinois. However, following federal and state recovery planning, populations are being restored in Illinois, Indiana, and Wisconsin. It now persists in about 150 populations, many of which are located on privately-owned land that is mowed each year. This mowing unfortunately often coincides with the flowering of this species, thus preventing sexual reproduction, and perpetuating the rarity of the species. (Bowles et al. 2001)

This species of milkweed differs from most other milkweeds by producing an unbranched stem that terminates in a single inflorescence projected above the top pair of leaves. Mature Mead's milkweed plants reach up to 20 inches high. They have 4-8 pairs of smooth blue-green leaves with a distinctive herringbone leaf-vein pattern. The nodding inflorescence contains about 12 flowers, which change from green to ivory as they mature, finally fading to a pale cream-color. The flowers produce large amounts of nectar and are pollinated by small bees.

Distribution & Occurrence

State Range
State Range of  Asclepias meadii
  Mead's milkweed has two habitats. Most populations occur in virgin tallgrass prairies or unplowed native prairie haymeadows that have well-drained, or dry-mesic, soils. Plants also occur in igneous glades in the Missouri Ozarks and in limestone glades in the Shawnee Hills of southern Illinois. Soil conditions in these habitats range from acid and nutrient poor in Missouri and southern Illinois to calcareous nutrient rich in Iowa and northern Illinois.

  Mead's milkweed is restricted to the tallgrass prairie region of the central United States (Harrison 1988, Betz 1989). It formerly ranged from eastern Kansas through Missouri and Illinois to southern Iowa, southwestern Wisconsin, and northwestern Indiana. Most populations now occur in 22 counties in Kansas and adjacent Missouri, and in 6 counties in southern Iowa. In Missouri, prairie populations occur in the Grand River Section of the Glaciated Plains Natural Division (Harrison County), the Springfield Plateau Section of the Ozarks Natural Division (parts of 6 counties) and in the Osage Plains Natural Division (parts of 9 counties). Igneous glades containing the species are within the St. Francois Mountain Section of the Ozark Natural Division (Iron & Reynolds counties).

Number Left
  There are about 150 remaining populations of Mead's milkweed. (Bowles et al. 2001)
Most populations are in privately owned prairie haymeadows in Kansas, where mowing removes developing seed pods and prevents sexual reproduction.
Only one Kansas population may be viable, where about 200 or more plants occur in a protected and fire-managed tallgrass prairie.
Fewer than 20 former haymeadow populations are preserved on public prairies in Missouri, and only one site contains a large population.
A second large, apparently viable, population occurs in fire-managed igneous glade habitat in southeastern Missouri, where several hundred or more plants are present.
The southern Iowa populations occupy prairie remnants and several haymeadows, and seed production has occurred at only one of these sites.
The southern Illinois population comprises four small colonies, each of which appears to be a single clone.


Global Rank:  
Guide to Global Ranks
Federal Status:  
Guide to Federal Status
Recovery Plan:  

State/Area Protection
  State/Area Rank Status Date  
  Illinois S1 LE 8/8/1989  
  Indiana SX SX 8/1/1989  
  Iowa S1 E 2/29/1988  
  Kansas S2 5/14/1987  
  Missouri S2 E  
  Wisconsin SX NONE 6/23/1992  

Conservation, Ecology & Research

Ecological Relationships
  Mead's milkweed is a rhizomatous perennial, and individual plants may persist for decades or longer.
This species is genetically diverse, and has a strongly enforced outcrossing breeding system. (Tecic et al. 1998)
Self-pollination rarely produces viable seeds, either due to self-incompatibility or severe inbreeding depression. As a result, small fragmented populations that persist by rhizomatous spread of a single clone do not produce seeds. Mowing for hay, which prevents sexual reproduction, also appears to cause vegetative spread and loss of genetic diversity within populations. (Tecic et al. 1998)
Dormant season fire has been found to promote flowering and seed production in this species, and relatively high levels of spring rainfall enhance seed germination and seedling establishment. Successful seedling establishment may occur infrequently and growth to flowering size may require ten or more years. As a result, population maintenance may depend upon extreme longevity of adult plants. (Bowles et al. 1998)

  Haymeadow populations in Kansas are threatened by urban development and agricultural expansion.
Haymowing of private or preserved prairies prevents seed production and leads to loss of genetic diversity.
Inbreeding and loss of genetic diversity appear to be major threats to small populations.

Current Research Summary
  Current demographic monitoring is being used to help understand whether the few larger preserved populations of Mead's milkweed are viable. The great longevity of adult plants could be masking slow long term demographic declines if rates of seedling establishment are below a threshold of viability.
Related research is also seeking to learn whether viable populations can be restored.
Tecic et al. (1998) studied the genetic diversity of the species.

Current Management Summary
  The Missouri Department of Conservation has management guidelines established for this species. (Smith 1997)
Populations of this species are being monitored in Illinois.

Research Management Needs
  Research is needed to determine whether practices such as haymowing and grazing can be compatible management schemes for viable milkweed populations.
Prescribed burning appears to be the most important management need for this species, as it promotes flowering and maintains tallgrass prairie habitat. In smaller populations, supplemental cross-pollination or introduction of compatible genotypes may be needed to promote seed production.

Ex Situ Needs
  The most important ex situ need is the maintenance of genetically diverse garden populations, as well as seed banks, that can serve as a resource for propagules used in population restoration.


Books (Single Authors)

1986. Flora of the Great Plains. Lawrence: University Press of Kansas.

1988. North American Terrestrial Vegetation. Cambridge: Cambridge University Press. 434p.

2000. Missouri Plants of Conservation Concern. Jefferson City, MO: Conservation Commission of Missouri--Missouri Department of Conservation.

Gleason, H.A. 1952. The New Britton and Brown illustrated flora of the northeastern United States and adjacent Canada. New York, NY: Hafner Press. 1732p.

Gleason, H.A.; Cronquist, A. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Bronx: The New York Botanical Garden.

Gray, A.; Fernald, M.L. 1987. Gray's manual of botany: a handbook of the flowering plants and ferns of the central and northeastern United States and adjacent Canada. Portland, Or.: Dioscorides Press. 1632p.

Herkert, J.; Ebinger, J.E. 2002. Endangered and threatened species of Illinois: Status and distribution. Springfield, IL: Illinois Endangered Species Protection Board. 161p.

Mohlenbrock, R.H. 1983. Where have all the wildflowers gone? A region-by-region guide to threatened or endangered U.S. wildflowers. New York: Macmillan Publishing Co. Inc. 239p.

Mohlenbrock, R.H. 1986. Guide to the Vascular Flora of Illinois. Carbondale, Illinois: Southern Illinois University Press. 507p.

Prior, J.C. 1976. A regional guide to Iowa landforms. Iowa City: Iowa Geological Survey. 72p.

Swink, F.; Wilhelm, G. 1994. Plants of the Chicago Region. Lisle, Illinois: The Morton Arboretum. 922p.

Voigt, J.W.; Mohlenbrock, R.H. 1964. Plant communities of southern Illinois. Carbondale, IL: Southern Illinois University Press. 202p.

WWF. 1990. The official World Wildlife Fund (WWF) guide to endangered species of North America. Washington, D.C.: Beacham Publishing. 1180p.

Books (Sections)

Gleason, H.A. 1968. The Sympetalous Dicotyledoneae. The New Britton and Brown Illustrated Flora of the Northeastern United States and Adjacent Canada. p 596.

Kartesz, J.T. 1999. A synonymized checklist of the vascular flora of the U.S., Canada, and Greenland. In: Kartesz, J.T.; Meacham, C.A., editors. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden. Chapel Hill, NC.

Schwegman, J. 1990. Preliminary results of a program to monitor plant species for management purposes. Ecosystem Management: Rare Species and Significant Habitats. New York State Museum Bulletin 471. New York.

Books (Edited Volumes)

Bowles, M.L.; Diersing, V.E; Ebinger, J.E.; Schultz, H.C. 1981 Endangered and threatened vertebrate animals and vascular plants of Illinois. Illinois Department of Conservation. 190p.

Conference Proceedings

Betz, R.F. Ecology of Mead's milkweed (Asclepias meadii Torrey). Proceedings of the 11th North American Prairie Conference; 1989; University of Nebraska, Lincoln. p 187-191.

Betz, R.F.; Struven, R.D.; Wall, J.E.; Heitler, F.B. Insect pollinators of 12 milkweed (Asclepias) species. Proceedings of the Thirteenth North American Prairie Conference; Windsor, Ontario, Canada: Department of Parks & Recreation. In: Woodliffe, A.; Pratt, P., editors. 1994. p 45-60.

Bowles, M.L.; Schaal, B.; Hayworth, D.; Williamson, K.; Tecic, D.; Nickrent, D. Management effects on population structure of Mead's milkweek (Asclepias meadii), a federal threatened prairie species. Abstracts from the 23rd Natural Areas, 15th North American Prairie, and Indiana Dunes Ecosystems Conferences,; 1996; St. Charles, IL.

Hayworth, D.; Bowles, M.L.; Schaal, B.; Williamson, K. Clonal population structure of the federal threatened Mead's Milkweed, as determined by RAPD analysis, and its conservation implications. Proceedings of the Seventeenth North American Prairie Conference: Seeds for the Future; Roots of the Past; Mason City Iowa: North Iowa Area Community College. In: Bernstein, N.; Ostrander, L.J., editors. 2001.

Electronic Sources

(2002). New York Botanical Garden--The Virtual Herbarium. [Searchable Web site] New York Botanical Garden. Fordham Road Bronx, New York. http://scisun.nybg.org:8890/searchdb/owa/wwwspecimen.searchform. Accessed: 2002.

ILDNR. (2002). Plant species biology summaries. Illinois Department of Natural Resources, Division of Natural Heritage, Botany Program. http://dnr.state.il.us/conservation/naturalheritage/botany/botany.htm. Accessed: 2002.

USGS. (2002). Status of Listed Species and Recovery Plan Development. [Web site] USGS: Norther Prairie Wildlife Research Center. http://www.npwrc.usgs.gov/resource/distr/others/recoprog/plant.htm. Accessed: 2002.

WIS. (2002). Wisconsin Vascular Plants--on species, including maps and photos. Wisconsin State Herbarium: University of Wisconsin - Madison (WIS). http://www.botany.wisc.edu/wisflora/. Accessed: 2002.

Journal Articles

Alexander, H.M.; Slade, N.A.; Kettle, W.D. 1997. Application of mark-recapture models to estimation of the population size of plants. Ecology. 78, 4: 1230-1237.

Allen, W.H. 1995. The Reintroduction Myth: Trying to save endangered plants by transplanting them fails as often as it succeeds. American Horticulturist. 33-37.

Axelrod, D.I. 1985. Rise of the grassland biome, central North America. Botanical Review. 51: 163-201.

Bowles, M.L.; McBride, J.L.; Bell, T. 2001. Restoration of the Federally Threatened Mead's Milkweed (Asclepias meadii). Ecological Restoration. 19, 4: 235-241.

Bowles, M.L.; McBride, J.L.; Betz, R.F. 1997. Restoration Ecology of Mead's milkweed. Annals of the Missouri Botanical Garden.

Bowles, M.L.; McBride, J.L.; Betz, R.F. 1998. Management and restoration ecology of the federal threatened Mead's milkweed, Asclepias meadii (Asclepiadaceae). Annals of the Missouri Botanical Garden. 85, 1: 110-125.

Harrison, W.F. 1988. Endangered and threatened wildlife and plants: Determination of threatened status for Mead's milkweed (Asclepias meadii). Federal Register. 53: 33992-33995.

Kephart, S.R. 1981. Breeding systems in Asclepias incarnata, Asclepias syriaca and Asclepias verticillata. American Journal of Botany. 68: 226-232.

Kephart, S.R.; Heiser, C.B. Jr. 1980. Reproductive isolation in Asclepias: Lock and key hypothesis reconsidered. Evolution. 34: 738-746.

Kettle, W.D.; Alexander, H.M.; Pittman, G.L. 2000. An 11-year ecological study of a rare prairie perennial (Asclepias meadii): Implications for monitoring and management. American Midland Naturalist. 144, 1: 66-77.

Lauver, C.L.; Whistler, J.L. 1993. A hierarchical-classification of landsat tm imagery to identify natural grassland areas and rare species habitat. Photogramm Eng Rem S. 59, 5: 627-634.

McGregor, R.L. 1987. Vascular flora of Kansas: New records and notes for 1986. Contributions of the University of Kansas Herbarium. 21: 1-8.

Rees, M.D. 1988. Final listing rules approved for 25 species. Endangered Species Technical Bulletin. 13, 9-10: 3-5.

Row, J.M.; Wynia, R.L. 2001. Mead's milkweed: Easy to germinate, difficult to establish (Kansas). Ecological Restoration. 19, 1: 49-50.

Schwegman, J.E. 1988. Illinoensis. Newsletter of the Illinois Native Plant Conservation Program. 4, 1: 4?.

Shannon, T.R.; Wyatt, R. 1986. Pollen germinability of Asclepias exaltata: effects of flower age, drying time, and pollen source. Systematic Botany. 11: 322-325.

Tecic, D.L.; McBride, J.L.; Bowles, M.L.; Nickrent, D.L. 1998. Genetic variability in the federal threatened Mead's milkweed, Asclepias meadii Torrey (Asclepiadaceae), as determined by allozyme electrophoresis. Annals of the Missouri Botanical Garden. 85, 1: 97-109.

U.S. Fish & Wildlife Service. 1987. Listing protection is proposed for seven species. Endangered Species Technical Bulletin. 12, 11-12: 5-6.

USFWS. 1976. Proposed Endangered Status for 1700 U.S. Plants. Federal Register. 41: 24523-24572.

USFWS. 1987. Final Listing Rules Approved for 10 Species. Endangered Species Technical Bulletin. 12, 11-12: 8.

USFWS. 1987. Proposal to determine Asclepias meadii (Mead's milkweed) to be threatened species. Federal Register. 52, 203: 39255-39258.

USFWS. 1988. Determination fo threatened status for Asclepias meadii (Mead's milkweed). Federal Register. 53: 33982-33994.

Willson, M.F.; Price, P.W. 1980. Resource limitation of fruit and seed production in some Asclepias species. Canadian Journal of Botany. 58: 2229-2233.

Woodson, R.E., Jr. 1954. The North American species of Asclepias L. Annals of the Missouri Botanical Garden. 41: 1-203.

Wyatt, R.; Broyles, S.B. 1994. Ecology and evolution of reproduction in milkweeds. Annual Review of Ecology and Systematics. 25: 423-441.

Magazine Articles

Ellis, D.J. 1995. Mead's milkweed. [Feature article]. American Horticulturist: 74. 8.

Rogers, G. 1988. Native Plants. Missouri Native Plant Society: 5. 1. 1-2.


1976. Endangered, threatened, and rare plants of the Shawnee National Forest (Illinois). Carbondale, IL: Biotic Consultants, Inc. p.39.

1990. Checklist of endangered and threatened animals and plants of Illinois. Springfield, IL: Illinois Endangered Species Protection Board and Illinois Department of Conservation.

1994. Mead's milkweed : A threatened species. Topeka, KS: Kansas State Board of Agriculture, Plant Health Division. (GovDoc: A 8.2:M 482).

Betz, R.F.; Hohn, J.E. 1978. Status report of Asclepias meadii. Denver: U.S. Fish & Wildlife Service. p.9.

Bowles, M.L. 1997. Mead's Milkweed (Asclepias meadii) recovery at the Morton Arboretum. Lisle, IL: The Morton Arboretum. p.1.

Bowles, M.L.; Bell, T. 1999. Recovery strategies and delisting criteria for Platanthera leucophaea, Asclepias meadii, Lespedeza leptostachya, Dalea foliosa, and Cirsium pitcheri. Springfield, IL: Report to the Illinois Endangered Species Protection Board.

Bowles, M.L.; McBride, J.L.; Betz, R.F. 1994. Propagation of Mead's Milkweed (Asclepias meadii) and its restoration in northeastern Illinois and adjacent Indiana. Lisle, IL: The Morton Arboretum. p.19.

Bowles, M.L.; Tecic, D.L.; Nickrent, D.L.; Schaal, B.; Hayworth, D.; Williamson, K. 1995. Recovery and restoration implications of DNA and allozyme variation in Mead's Milkweed. The Morton Arboretum, Southern Illinois University, and Washington University.

Busby, W.H. 1990. An inventory of three prairie animals in eastern Kansas. Kansas Department of Wildlife and Parks. p.17.

Figg, D.E.; Calvert, P.D. 1987. Status, distribution and life history of the prairie mole cricket, Gryllotalpa major Saussure. Jefferson City, Missouri: Missouri Department of Conservation. p.40.

Freeman, C.C. 1988. ESIS workbook for Asclepias meadii. U.S. Fish & Wildlife Service.

Kurz, D.R.; Bowles, M.L. 1981. Status report of Asclepias meadii. Springfield, IL: llinois Dept. of Conservation. p.8.

Litzow, M. 1978. Asclepias meadii Torr.: A summary of the literature. St. Paul, MN: Univ. of Minnesota Landscape Arboretum, unpublished report. p.4.

Locklear, J. 1987. Plant Conservation Activities: 1987 Annual Report. Lincoln, NE: From the Nebraska Statewide Arboretum to the Center for Plant Conservation. p.3.

Morgan, S.W. 1980. Status report on Asclepias meadii Torr. Jefferson City: Missouri Department of Conservation. p.15.

Read, Robert H. 1976. Endangered and threatened vascular plants of Wisconsin, Technical Bulletin No. 92. Madison, WI: Scientific Areas Preservation Council, Department of Natural Resources. p.58.

Schwegman, J. 1987. Procedures for census, demographic monitoring, compiling life history information, and development of management guidelines for special plants. Springfield, IL: Unpublished report, Illinois Department of Conservation. p.21.

Schwegman, J. 1990. Illinois 1990 endangered and threatened plant status. Springfield, IL: Illinois Department of Conservation.

Schwegman, J. 1993. Illinois 1993 Endangered & Threatened Plant Status. Botany Program, Natural Heritage Division, Illinois Department of Conservation.

Smith, T. 1997. Management guidelines for Mead's milkweed (Asclepias meadii Torrey ex A. Gray). Jefferson City, Missouri: Missouri Department of Conservation.

Thurman, C.M. 1989. Final Report. A Missouri survey of six species of federal concern. Missouri Dept. of Conservation. p.99.

Thurman, C.M.; Hickey, E.E. 1989. A Missouri survey of six species of federal concern: Auriculate False Foxglove, Tomanthera auriculata; Mead's Milkweed, Asclepias meadii; Geocarpon, Geocarpon minimum; Missouri Bladder-pod, Lesquerella filiformis; Western Prairie Fringed Orchid, Platanthera praeclara; and Decurrent False Aster, Boltonia decurrens. Missouri Dept. of Conservation.

USFWS. 1990. Recovery plan for Mead's milkweed (Ascleias meadii Torr.): Technical Draft. Twin Cities, MN: U.S. Fish & Wildlife Service. p.30.

USFWS. 1994. Draft Illinois recovery plan for Mead's milkweed (Asclepias meadii Torr.). U.S. Fish & Wildlife Service.

Watson, William C. 1992. Inventory of southern Iowa for Asclepias meadii Torr. Des Moines, IA: Iowa Dept. of Natural Resources.

  This profile was updated on 9/28/2010
New Mexico
North Dakota
South Dakota
South Carolina
North Carolina
West Virginia
New Jersey
Rhode Island
New Hampshire
New York
New York