Index of Species Information

SPECIES:  Asclepias incarnata

Introductory

SPECIES: Asclepias incarnata




AUTHORSHIP AND CITATION : 
Pavek, Diane S. 1992. Asclepias incarnata. In: Fire Effects Information System, [Online]. 
U.S. Department of Agriculture, Forest Service, 
Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). 
Available: http://www.fs.fed.us/database/feis/ [].




ABBREVIATION : 
ASCINC

SYNONYMS : 
   Asclepias pulchra Ehrh. ex Willd.


SCS PLANT CODE : 
   ASIN


COMMON NAMES : 
   swamp milkweed
   milkweed


TAXONOMY : 
The currently accepted scientific name of swamp milkweed is Asclepias incarnata L.
(Asclepidaceae).  There is disagreement in the taxonomic literature
about infrataxa treatment.  Two subspecies are recognized:

     Asclepias incarnata ssp. incarnata [23]
     A. i. ssp. pulchra (Ehrh. ex Willd.) Woods. [23]

Also recognized are the following variety and forms:

     A. i. var. incarnata f. incarnata [21]
     A. i. var. incarnata f. albiflora--Found only in Missouri [21]
     A. i. var. incarnata f. rosea Bowin--Found only in southern
                                          Ontario, Canada [18].

This report does not use infrataxa; they rarely appear in the
literature.


LIFE FORM : 
Forb

FEDERAL LEGAL STATUS : 
No special status

OTHER STATUS : 
NO-ENTRY





DISTRIBUTION AND OCCURRENCE

SPECIES: Asclepias incarnata




GENERAL DISTRIBUTION : 
Swamp milkweed is found throughout the eastern and midwestern United
States and Canada.  It occurs from Prince Edward Island and Maine west
to southern Manitoba [20,23,21].  Swamp milkweed continues southeast
through the Midwest and Great Plains to Florida [6,15,18].  Its
distribution extends westward to Texas and New Mexico [2,20,24].  Six
disjunct areas of its range occur in southern Idaho, Wyoming, Nevada,
and north, central, and south Utah [3,26].


ECOSYSTEMS : 
   FRES12  Longleaf - slash pine
   FRES13  Loblolly - shortleaf pine
   FRES15  Oak - hickory
   FRES16  Oak - gum - cypress
   FRES28  Western hardwoods


STATES : 
     AZ  CT  FL  GA  ID  IL  IN  LA  ME  MA
     MI  MN  MO  NV  NH  NM  ND  OK  RI  SC
     SD  TN  TX  UT  VT  VA  WI  WY  MB  NB
     NS  ON  PE  PQ



BLM PHYSIOGRAPHIC REGIONS : 
    6  Upper Basin and Range
    8  Northern Rocky Mountains
   10  Wyoming Basin
   11  Southern Rocky Mountains
   12  Colorado Plateau
   13  Rocky Mountain Piedmont
   14  Great Plains


KUCHLER PLANT ASSOCIATIONS : 
   K025  Alder - ash forest
   K081  Oak savanna
   K082  Mosaic of K074 and K100
   K084  Cross Timbers
   K089  Black Belt
   K090  Live oak - sea oats
   K091  Cypress savanna
   K100  Oak - hickory forest
   K104  Appalachian oak forest
   K105  Mangrove
   K110  Northeastern oak - pine forest
   K111  Oak - hickory - pine forest
   K112  Southern mixed forest
   K113  Southern floodplain forest
   K114  Pocosin
   K115  Sand pine scrub
   K116  Subtropical pine forest


SAF COVER TYPES : 
    45  Pitch pine
    50  Black locust
    53  White oak
    55  Northern red oak
    57  Yellow-poplar
    58  Yellow-poplar - eastern hemlock
    59  Yellow-poplar - white oak - northern red oak
    61  River birch - sycamore
    64  Sassafras - persimmon
    65  Pin oak - sweetgum
    69  Sand pine
    70  Longleaf pine
    73  Southern redcedar
    75  Shortleaf pine
    79  Virginia pine
    80  Loblolly pine - shortleaf pine
    81  Loblolly pine - shortleaf pine
    83  Longleaf pine - slash pine
    84  Slash pine
    87  Sweet gum - yellow-poplar
    88  Willow oak - water oak - diamondleaf oak
    89  Live oak
    91  Swamp chestnut oak - cherrybark oak
    96  Overcup oak - water hickory
    97  Atlantic white cedar
   101  Baldcypress
   102  Baldcypress - tupelo
   103  Water tupelo - swamp tupelo
   104  Sweetbay - swamp tupelo - redbay
   105  Tropical hardwoods
   109  Hawthorn
   110  Black oak
   111  South Florida slash pine
   222  Black cottonwood - willow
   235  Cottonwood - willow
   252  Paper birch


SRM (RANGELAND) COVER TYPES : 
NO-ENTRY


HABITAT TYPES AND PLANT COMMUNITIES : 
NO-ENTRY









MANAGEMENT CONSIDERATIONS

SPECIES: Asclepias incarnata






IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Swamp milkweed foliage and stems have been reported to cause mortality
in sheep.  It is not known why sheep are so susceptible [7,12].
Muskrats are unaffected by swamp milkweed and readily eat the roots
[23].


PALATABILITY : 
Milkweeds in general are not palatable to wildlife.  The bitter milky
juice is high in alkaloids [17].  Most animals avoid it unless forced to
eat it on overgrazed pastures [17].


NUTRITIONAL VALUE : 
NO-ENTRY


COVER VALUE : 
NO-ENTRY


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Swamp milkweed is currently used in Wisconsin for wetland rehabilitation
[11].  It is included in commercially available seed mixes.


OTHER USES AND VALUES : 
Swamp milkweed seeds have long hairs, called comas.  Seed comas have
been used as pillow and lifejacket stuffing [3,23].  Stem fibers have
been suggested as substitutes for flax and hemp [3].  Young shoots,
inflorescences, and leaves may be cooked with several changes of water
and eaten [23].  This plant causes dermititis.


OTHER MANAGEMENT CONSIDERATIONS : 
NO-ENTRY









BOTANICAL AND ECOLOGICAL CHARACTERISTICS

SPECIES: Asclepias incarnata




GENERAL BOTANICAL CHARACTERISTICS : 
Swamp milkweed is an erect plant, 11 to 18 inches (0.3-0.5 m) tall, with
milky sap.  It has a short rootstock or caudex with shallow fibrous
roots.  A plant may have one to several leafy stems.  Its lance-shaped,
opposite leaves have short stalks.  Flowers have many elaborate
structures (e.g., hoods and horns) and are arranged in flesh-colored
terminal umbels [23].


RAUNKIAER LIFE FORM : 
   Hemicryptophyte


REGENERATION PROCESSES : 
Swamp milkweed readily germinates from seed shed the previous year (50
to 88 percent germination [11]) after cold stratification, 39 degrees
Fahrenheit (4 deg C), for approximately 9 months.  A plant puts up an
average of one stem from a short caudex and sprouts each year from this
rootstock.  Flowers are insect pollinated (Hymenoptera and Lepidoptera)
[10].  Seeds have long hairs that facilitate wind dispersal in the fall.
Swamp milkweed is self-fertile [8].  It very rarely reproduces asexually
by rhizomes [8].


SITE CHARACTERISTICS : 
Swamp milkweed is a semiaquatic plant [3].  It occurs in a range of wet
conditions from standing water to saturated soil.  A riparian species,
it is found on streambanks, pond shores, banks, and floodplains of
lakes, waterways, marshes, swamps, and wet areas of prairies
[6,13,18,21].  Additionally, it occurs in wet meadows and in low wet
woods [23].


SUCCESSIONAL STATUS : 
Swamp milkweed is a colonizer.  It has wind-dispersed seeds and can
self-fertilize.


SEASONAL DEVELOPMENT : 
Across its range, swamp milkweed begins to flower during the last week
of June or the first week in July and continues until August or
September [2,6,15,18,21,23].  Individual flowers remain open for about 1
week [9].  Fruits mature from August through October [2,6,15,18,21,23].
After maturation, follicles split open on one side to release seeds
during October and November [23].









FIRE ECOLOGY

SPECIES: Asclepias incarnata




FIRE ECOLOGY OR ADAPTATIONS : 
The moist habitat of swamp milkweed discourages fire entry.  Swamp
milkweed is very shallowly rooted; it would most likely be killed in a
fire of any severity.  Adjacent communities may serve as seed sources
after a fire.  Swamp milkweed is a component of prairie wetlands, so it
has evolved with some fire exposure.


POSTFIRE REGENERATION STRATEGY : 
   survivor species; on-site surviving root crown or caudex
   off-site colonizer; seed carried by wind; postfire years 1 and 2









FIRE EFFECTS

SPECIES: Asclepias incarnata




IMMEDIATE FIRE EFFECT ON PLANT : 
No fire studies on this plant have been reported.  A fire would kill
swamp milkweed back to the caudex.  In moist soil, the caudex is usually
not deeply rooted.  Death would depend upon fire severity.  It may
survive a cool fire.  Late season (summer and fall) fires would have the
greatest effect on this species.  Since its seeds are not shed until
October or November, a late season fire would kill the seed crop of the
current year.


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Following a cool surface fire, swamp milkweed sprouts from the caudex
and produces fruit.  If plants have been killed, off-site seeds will be
wind dispersed into the burned area.  This seed will germinate on burned
areas during the first postfire growing season, provided soil conditions
are wet.

Long-term response:  Swamp milkweed should have no difficulties in
maintaining populations.  It can self-fertilize; sexual reproduction
will continue, despite a reduced number of colonizing plants.

Plant recovery is controlled by the severity of the fire and
availability of adequately wet habitat.


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
NO-ENTRY

References for species: Asclepias incarnata

1. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434]
2. Correll, Donovan S.; Johnston, Marshall C. 1970. Manual of the vascular plants of Texas. Renner, TX: Texas Research Foundation. 1881 p. [4003]
3. Cronquist, Arthur; Holmgren, Arthur H.; Holmgren, Noel H.; [and others]. 1984. Intermountain flora: Vascular plants of the Intermountain West, U.S.A. Vol. 4. Subclass Asteridae, (except Asteraceae). New York: The New York Botanical Garden. 573 p. [718]
4. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]
5. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998]
6. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. [1603]
7. Hansen, Albert A. 1924. Robitin--a potent plant poison. Better Crops. 2(2): 22-23; 44. [29437]
8. Kephart, Susan R. 1981. Breeding systems in Asclepias incarnata L., A. syriaca L., and A. verticillata L. American Journal of Botany. 68: 226-232. [18147]
9. Kephart, Susan R. 1987. Phenological variation in flowering and fruiting of Asclepias. The American Midland Naturalist. 118(1): 64-76. [18146]
10. Kephart, Susan R.; Heiser, Charles B., Jr. 1980. Reproductive isolation in Asclepias: lock and key hypothesis reconsidered. Evolution. 34(4): 738-746. [18148]
11. Kerans, Karen. 1990. Country Wetlands Nursery Ltd. Restoration & Management Notes. 8(1): 29-31. [14513]
12. Kingsbury, John M. 1964. Poisonous plants of the United States and Canada. Englewood Cliffs, NJ: Prentice-Hall, Inc. 626 p. [122]
13. Kron, Kathleen A. 1989. The vegetation of Indian Bowl wet prairie and its adjacent plant communities. II. Checklist of vascular plants. Michigan Botanist. 28(4): 201-215. [17359]
14. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384]
15. Lakela, O. 1965. A flora of northeastern Minnesota. Minneapolis, MN: University of Minnesota Press. 541 p. [18142]
16. Lyon, L. Jack; Stickney, Peter F. 1976. Early vegetal succession following large northern Rocky Mountain wildfires. In: Proceedings, Tall Timbers fire ecology conference and Intermountain Fire Research Council fire and land management symposium; 1974 October 8-10; Missoula, MT. No. 14. Tallahassee, FL: Tall Timbers Research Station: 355-373. [1496]
17. Muenscher, W. C. 1940. Poisonous plants of the United States. New York: MacMillan Co. 266 p. [18141]
18. Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of the vascular flora of the Carolinas. Chapel Hill, NC: The University of North Carolina Press. 1183 p. [7606]
19. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]
20. Scoggan, H. J. 1978. The flora of Canada. Ottawa, Canada: National Museums of Canada. (4 volumes) [18143]
21. Seymour, Frank Conkling. 1982. The flora of New England. 2d ed. Phytologia Memoirs 5. Plainfield, NJ: Harold N. Moldenke and Alma L. Moldenke. 611 p. [7604]
22. Shipley, B.; Parent, M. 1991. Germination responses of 64 wetland species in relation to seed size, minimum time to reproduction and seedling relative growth rate. Functional Ecology. 5(1): 111-118. [14554]
23. Steyermark, J. A. 1963. Flora of Missouri. Ames, IA: Iowa State University Press. 1725 p. [18144]
24. Tidestrom, I.; Kittell, T. 1941. A flora of Arizona and New Mexico. Washington, DC: The Catholic University of America Press. 897 p. [18145]
25. U.S. Department of Agriculture, Soil Conservation Service. 1982. National list of scientific plant names. Vol. 1. List of plant names. SCS-TP-159. Washington, DC. 416 p. [11573]
26. Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; Higgins, Larry C., eds. 1987. A Utah flora. The Great Basin Naturalist Memoir No. 9. Provo, UT: Brigham Young University. 894 p. [2944]


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