Asclepias tuberosa - L.
Butterfly Milkweed
Other Common Names: butterfly milkweed
Taxonomic Status: Accepted
Related ITIS Name(s): Asclepias tuberosa L. (TSN 30313)
Unique Identifier: ELEMENT_GLOBAL.2.129775
Element Code: PDASC02210
Informal Taxonomy: Plants, Vascular - Flowering Plants - Dogbane Family
 
Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Dicotyledoneae Gentianales Apocynaceae Asclepias
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Concept Reference
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Concept Reference: Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Asclepias tuberosa
Taxonomic 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).
Conservation Status
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NatureServe Status

Global Status: G5
Global Status Last Reviewed: 28Jun2016
Global Status Last Changed: 28Jun2016
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: 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.
Nation: United States
National Status: N5?
Nation: Canada
National Status: N4 (28Jun2016)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (SNR), Arizona (SNR), Arkansas (SNR), California (SNR), Colorado (SNR), Connecticut (SNR), Delaware (SNR), District of Columbia (SNR), Florida (SNR), Georgia (S5), Illinois (SNR), Indiana (SNR), Iowa (S4), Kansas (SNR), Kentucky (S5), Louisiana (SNR), Maine (SX), Maryland (SNR), Massachusetts (S4), Michigan (SNR), Minnesota (SNR), Mississippi (SNR), Missouri (SNR), Nebraska (SNR), New Hampshire (SH), New Jersey (SNR), New Mexico (SNR), New York (SNR), North Carolina (S5), Ohio (SNR), Oklahoma (SNR), Pennsylvania (S5), Rhode Island (SNR), South Carolina (SNR), South Dakota (SNR), Tennessee (SNR), Texas (SNR), Utah (SNR), Vermont (SH), Virginia (S5), West Virginia (S5), Wisconsin (SNR)
Canada Ontario (S4), Quebec (S1)

Other Statuses

NatureServe Global Conservation Status Factors

Range Extent Comments: 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).

Number of Occurrences: 81 to >300
Number of Occurrences 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).

Overall Threat Impact 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).

Short-term Trend: Decline of 10-30%
Short-term Trend 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.

Other NatureServe Conservation Status Information

Distribution
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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).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map

U.S. & Canada State/Province Distribution
United States AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, MEextirpated, MI, MN, MO, MS, NC, NE, NH, NJ, NM, NY, OH, OK, PA, RI, SC, SD, TN, TX, UT, VA, VTnative and exotic, WI, WV
Canada ON, QC

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
MA Barnstable (25001), Berkshire (25003), Bristol (25005), Dukes (25007), Essex (25009)*, Franklin (25011), Hampden (25013), Hampshire (25015)*, Middlesex (25017), Nantucket (25019), Plymouth (25023), Worcester (25027)
ME York (23031)*
NH Carroll (33003)*, Cheshire (33005)*, Hillsborough (33011)*, Merrimack (33013)*, Rockingham (33015)*, Sullivan (33019)*
RI Kent (44003)*
VA Isle of Wight (51093), Southampton (51175), Suffolk (City) (51800)
VT Bennington (50003)*
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
01 Presumpscot (01060001)+*, Merrimack (01070002)+*, Nashua (01070004)+*, Merrimack (01070006)+*, Black-Ottauquechee (01080106)+*, West (01080107)+*, Middle Connecticut (01080201)+*, Chicopee (01080204)+, Lower Connecticut (01080205)+, Westfield (01080206)+, Charles (01090001)+, Cape Cod (01090002)+, Blackstone (01090003)+, Narragansett (01090004)+, Housatonic (01100005)+
02 Hudson-Hoosic (02020003)+*
03 Nottoway (03010201)+, Blackwater (03010202)+, Ghowan (03010203)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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Basic Description: Asclepias tuberosa is a perennial herb of North American prairies and dry woods. It averages about 0.5m in height, and is distinguished from other milkweeds by its alternately arranged leaves, its bright orange or yellow flowers, and sap which doesn't have a milky consistency (Gleason and Cronquist 1963).
Habitat 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).
Economic Attributes
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Economically Important Genus: Y
Economic Uses: FOOD, MEDICINE/DRUG, FIBER
Production Method: Cultivated, Wild-harvested
Economic 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.).
Management Summary Not yet assessed
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Population/Occurrence Delineation
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Minimum Criteria for an Occurrence: In terms of habitat suitability for A. tuberosa, it appears that average conditions are moister than ideal in the eastern one-third of its range, ideal in the central one-third of its range, and too dry in the western one-third of its range. To the extent that this is true A. tuberosa is restricted to suitable habitat in the eastern and western portions of its range, and could be far more widespread (continuously distributed) in the central portion of its range. Ironically, natural communities in the central portion of its range have been mostly destroyed for agriculture. In addition to habitat constraints, habitat fragmentation is now likely an important separator of populations in the eastern and western portions of the range.


Date: 21Jan2000
Author: Spackman, S.
Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
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Authors/Contributors
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NatureServe Conservation Status Factors Edition Date: 27Feb2000
NatureServe Conservation Status Factors Author: Susan Spackman, David Anderson, and Steve Thomas (1/00); rev. Eric Nielsen (1/00), rev. L. Morse (2000)

Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

References
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  • Cronquist, A., A.H. Holmgren, N.H. Holmgren, J.L. Reveal, and P.K. Holmgren. 1984. Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. Vol. 4, Subclass Asteridae (except Asteraceae). New York Botanical Garden, Bronx. 573 pp.

  • Culver, D. R. and J. M. Lemly. 2013a. Field Guide to Colorado's Wetland Plants. Colorado Natural Heritage Program. Colorado State University. 694 pp.

  • Deam, C. C. 1940. Flora of Indiana. Division of Forestry, Dept. of Conservation, Indianapolis, Indiana. 1236 pp.

  • Great Plains Flora Association. 1986. Flora of the Great Plains. University Press of Kansas, Lawrence, KS.

  • Great Plains Flora Association. 1986. Flora of the Great Plains. University Press of Kansas, Lawrence, KS. 1402 pp.

  • Great Plains Flora Association. 1986. Flora of the Great Plains. University of Kansas Press, Lawrence. 1392 pp.

  • Groh, H. 1927. Asclepias tuberosa L. in the Ottawa District. Canadian Field-Naturalist 41(9): 202.

  • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

  • Kartesz, J.T. 1996. Species distribution data at state and province level for vascular plant taxa of the United States, Canada, and Greenland (accepted records), from unpublished data files at the North Carolina Botanical Garden, December, 1996.

  • Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.

  • Niering, W.A. and N.C. Olmstead. 1979. The Audubon Society Field Guide to North American Wildflowers, Eastern Region. Alfred A. Knopf, Inc., New York. 887 pp.

  • Peterson, L. 1977a. A Field Guide to Edible Wild Plants of Eastern and Central North America. Houghton Mifflin Co., Boston, Massachusetts. 330 p. + plates.

  • Peterson, L.A. 1977. A Field Guide to Edible Wild Plants, Eastern/Central North America. Houghton Mifflin Company, Boston. 330 pp.

  • Swink, F., and G. Wilhelm. 1994. Plants of the Chicago Region. Morton Arboretum. Lisle, Illinois.

  • U.S. Department of Agriculture, Natural Resources Conservation Service. 1999. November 3-last update. The PLANTS database. Online. Available: http://plants.usda.gov/plants. Accessed 2000-Jan.

  • Weber, W.A. and Ronald Wittmann. 1996. Colorado Flora: Western Slope. University Press of Colorado.

  • Weber, W.A., and R.C. Wittmann. 1996a. Colorado flora: Eastern slope. Revised edition. Univ. Press of Colorado, Niwot, Colorado. 524 pp.

  • Weber, W.A., and R.C. Wittmann. 1996b. Colorado flora: Western slope. Univ. Press of Colorado, Niwot, Colorado. 496 pp.

  • Weiner, M.A. 1980. Earth Medicine Earth Food. Ballantine Books, New York. 230 pp.

  • Weiner, M.A. 1980. Earth Medicine Earth Food. Ballantine Books, New York. 230 pp.

  • Welsh, S.L, N.D. Atwood, S. Goodrich, and L.C. Higgins. 1993. A Utah Flora, second edition, revised. Brigham Young University, Provo, UT.

  • Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins (eds.) 1993. A Utah flora. 2nd edition. Brigham Young Univ., Provo, Utah. 986 pp.

  • Woodson, R.E., Jr. 1944. Notes on some North American Asclepiads. Annals of the Missouri Botanical Garden 31: 363-369.

  • Woodson, R.E., Jr. 1947. Some dynamics of leaf variation in Asclepias tuberosa. Annals of the Missouri Botanical Garden 34(4): 353-432.

  • Wyatt, R., and J. Antonovics. 1981. Butterflyweed re-revisited: spatial and temporal patterns of leaf shape variation in Asclepias tuberosa. Evolution 35(3):529-542.

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