Asclepias: Difference between revisions

Jump to navigation Jump to search
VisualWikitext
No edit summary
No edit summary
 
(2 intermediate revisions by 2 users not shown)
Line 4: Line 4:


==Overview==
==Overview==
'''''Asclepias''''' [[Carolus Linnaeus|L.]] (1753), the '''milkweeds''', is an American [[genus]] of herbaceous [[perennial plant|perennial]], [[dicotyledon]]ous [[plant]]s  that contains over 140 known species. It previously belonged to the [[family (biology)|family]] Asclepiadaceae, but this is now classified as the [[Family (biology)|subfamily]] [[Asclepiadoideae]] of the dogbane family [[Apocynaceae]].
'''''Asclepias''''' [[Carolus Linnaeus|L.]] (1753), the '''milkweeds''', is an American [[genus]] of herbaceous [[perennial plant|perennial]], [[dicotyledon]]ous [[plant]]s  that contains over 140 known species. It previously belonged to the [[family (biology)|family]] Asclepiadaceae, but this is now classified as the [[Family (biology)|subfamily]] Asclepiadoideae of the dogbane family [[Apocynaceae]].


Milkweed is named for its milky sap, which consists of a [[latex]] containing [[alkaloid]]s and several other complex compounds including [[cardenolide]]s.<ref>Singh, B. and Rastogi, R.P. (1970). Cardenolides-glycosides and genins. Phytochemistry 9: 315-331.</ref> Some species are known to be [[toxic]].
Milkweed is named for its milky sap, which consists of a [[latex]] containing [[alkaloid]]s and several other complex compounds including [[cardenolide]]s.<ref>Singh, B. and Rastogi, R.P. (1970). Cardenolides-glycosides and genins. Phytochemistry 9: 315-331.</ref> Some species are known to be [[toxic]].
Line 11: Line 11:


== Milkweed flowers ==
== Milkweed flowers ==
Asclepias species produce some of the most complex flowers in the plant kingdom, comparable to [[orchids]] in complexity. Five petals reflex backwards revealing a gynostegium (fused stamen filamens and styles) surrounded by a  five-membered corona. The corona is composed of a five paired hood and horn structures with the hood acting as a sheath for the inner horn. Glands holding pollinia are found between the hoods. The size, shape and color of the horns and hoods are often important identifying characteristics for species in the genus Asclepias.<ref>http://orbisec.com/milkweed-flower-morphology-and-terminology/ Milkweed Flower Morphology</ref>
Asclepias species produce some of the most complex flowers in the plant kingdom, comparable to orchids in complexity. Five petals reflex backwards revealing a gynostegium (fused stamen filamens and styles) surrounded by a  five-membered corona. The corona is composed of a five paired hood and horn structures with the hood acting as a sheath for the inner horn. Glands holding pollinia are found between the hoods. The size, shape and color of the horns and hoods are often important identifying characteristics for species in the genus Asclepias.<ref>http://orbisec.com/milkweed-flower-morphology-and-terminology/ Milkweed Flower Morphology</ref>
   
   
[[Pollination]] in this genus is accomplished in an unusual manner. [[Pollen]] is grouped into complex structures called [[pollinia]] (or "pollen sacs"), rather than being individual grains or tetrads, as is typical for most plants. The feet or mouthparts of flower-visiting insects such as [[bee]]s, [[wasp]]s and [[Butterfly|butterflies]], slip into one of the five slits in each flower formed by adjacent [[anther]]s. The bases of the pollinia then mechanically attach to the insect, so that a pair of pollen sacs can be pulled free when the pollinator flies off, assuming the insect is large enough to produce the necessary pulling force (if not, the insect may become trapped and die).<ref name = "Robertson">Robertson, C. (1887) Insect relations of certain asclepiads. I. Botanical Gazette 12: 207–216</ref> Pollination is effected by the reverse procedure in which one of the pollinia becomes trapped within the anther slit.
[[Pollination]] in this genus is accomplished in an unusual manner. [[Pollen]] is grouped into complex structures called pollinia (or "pollen sacs"), rather than being individual grains or tetrads, as is typical for most plants. The feet or mouthparts of flower-visiting insects such as [[bee]]s, [[wasp]]s and Butterfly|butterflies, slip into one of the five slits in each flower formed by adjacent anthers. The bases of the pollinia then mechanically attach to the insect, so that a pair of pollen sacs can be pulled free when the pollinator flies off, assuming the insect is large enough to produce the necessary pulling force (if not, the insect may become trapped and die).<ref name = "Robertson">Robertson, C. (1887) Insect relations of certain asclepiads. I. Botanical Gazette 12: 207–216</ref> Pollination is effected by the reverse procedure in which one of the pollinia becomes trapped within the anther slit.
 
[[File:Bee on Antelope Horn-April 2015.JPG|thumb|Honeybee on antelope horn (''[[Asclepias asperula]]'') with pollinia attached to legs]]


''Asclepias'' species produce their [[seed]]s in [[Follicle (fruit)|follicles]]. The seeds, which are arranged in overlapping rows, bear a cluster white, silky, filament-like hairs known as the '''coma'''<ref>Sacchi, C.F. (1987) Variability in dispersal ability of Common Milkweed, ''Asclepias syriaca'', seeds, [[Oikos]] Vol. 49, pp. 191-198</ref> (often referred to by other names such as [[Pappus (flower structure)|pappus]], "floss", "plume", or "silk"). The follicles ripen and split open, and the seeds, each carried by its coma, are blown by the [[Seed dispersal#Wind|wind]].
''Asclepias'' species produce their [[seed]]s in [[Follicle (fruit)|follicles]]. The seeds, which are arranged in overlapping rows, bear a cluster white, silky, filament-like hairs known as the '''coma'''<ref>Sacchi, C.F. (1987) Variability in dispersal ability of Common Milkweed, ''Asclepias syriaca'', seeds, [[Oikos]] Vol. 49, pp. 191-198</ref> (often referred to by other names such as [[Pappus (flower structure)|pappus]], "floss", "plume", or "silk"). The follicles ripen and split open, and the seeds, each carried by its coma, are blown by the [[Seed dispersal#Wind|wind]].
Line 22: Line 20:
== Ecology ==
== Ecology ==


American milkweeds are an important [[nectar]] source for native [[bee]]s, [[wasp]]s, and other nectar-seeking insects, though non-native [[Western honey bee|honey bees]] commonly get trapped in the stigmatic slits and die,<ref name = "Robertson"/><ref>Frost, S.W. (1965) Insects and pollinia. Ecology 46: 556–558</ref> and a larval food source for [[Monarch (butterfly)|monarch butterflies]] and their relatives, as well as a variety of other herbivorous insects (including numerous [[beetle]]s, [[moth]]s, and [[true bug]]s) specialized to feed on the plants despite their [[Plant defense against herbivory|chemical defenses]].
American milkweeds are an important nectar source for native [[bee]]s, [[wasp]]s, and other nectar-seeking insects, though non-native [[Western honey bee|honey bees]] commonly get trapped in the stigmatic slits and die,<ref name = "Robertson"/><ref>Frost, S.W. (1965) Insects and pollinia. Ecology 46: 556–558</ref> and a larval food source for Monarch (butterfly)|monarch butterflies and their relatives, as well as a variety of other herbivorous insects (including numerous beetles, moths, and true bugs) specialized to feed on the plants despite their Plant defense against herbivory|chemical defenses.


Milkweeds use three primary defenses to limit damage caused by [[caterpillar]]s: hairs on the leaves, [[cardenolide]] toxins, and [[latex]] fluids.  Data from a [[DNA]] study indicate that more recently evolved milkweed species use these preventative strategies less but grow faster than older species, potentially regrowing faster than caterpillars can consume them.<ref>{{cite journal |last=Ramanujan |first=Krishna |date=Winter 2008|title=Discoveries: Milkweed evolves to shrug off predation |journal=Northern Woodlands |volume=15 |issue=4 |page=56 |publisher=Center for Northern Woodlands Education |url= |accessdate= }}</ref>
Milkweeds use three primary defenses to limit damage caused by caterpillars: hairs on the leaves, [[cardenolide]] toxins, and [[latex]] fluids.  Data from a [[DNA]] study indicate that more recently evolved milkweed species use these preventative strategies less but grow faster than older species, potentially regrowing faster than caterpillars can consume them.<ref>{{cite journal |last=Ramanujan |first=Krishna |date=Winter 2008|title=Discoveries: Milkweed evolves to shrug off predation |journal=Northern Woodlands |volume=15 |issue=4 |page=56 |publisher=Center for Northern Woodlands Education |url= |accessdate= }}</ref>


== Uses ==
== Uses ==


The milkweed filaments from the coma (the "floss") are hollow and coated with [[wax]], and have good [[Thermal insulation|insulation]] qualities. During [[World War II]], over  of milkweed floss were collected in the United States as a substitute for [[kapok]]. As of 2007, milkweed is grown commercially as a [[hypoallergenic]] filling for pillows.<ref>{{Cite journal | author = Evangelista, R.L. | year = 2007 | title = Milkweed seed wing removal to improve oil extraction | journal = Industrial Crops and Products | volume = 25 | issue = 2 | pages = 210–217 | doi = 10.1016/j.indcrop.2006.10.002 }}</ref> A study of the insulative properties of various materials found that milkweed floss was outperformed by other materials in insulation, loft, and lumpiness, but scored well on various metrics when mixed with down feathers.<ref name= TRJ1991>{{cite journal |last=McCullough|first=Elizabeth A.|title=Evaluation of Milkweed Floss as an Insulative Fill Material |journal=Textile Research Journal|date=April 1991 |volume=61 |issue=4 |pages=203–210|url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1009&context=textiles_facpub |doi=10.1177/004051759106100403}}</ref> Milkweed fibers are used to clean up oil spills.<ref>http://www.cbc.ca/news/politics/milkweed-touted-as-oil-spill-super-sucker-with-butterfly-benefits-1.2856029</ref>
The milkweed filaments from the coma (the "floss") are hollow and coated with [[wax]], and have good [[Thermal insulation|insulation]] qualities. During World War II, over  of milkweed floss were collected in the United States as a substitute for kapok. As of 2007, milkweed is grown commercially as a [[hypoallergenic]] filling for pillows.<ref>{{Cite journal | author = Evangelista, R.L. | year = 2007 | title = Milkweed seed wing removal to improve oil extraction | journal = Industrial Crops and Products | volume = 25 | issue = 2 | pages = 210–217 | doi = 10.1016/j.indcrop.2006.10.002 }}</ref> A study of the insulative properties of various materials found that milkweed floss was outperformed by other materials in insulation, loft, and lumpiness, but scored well on various metrics when mixed with down feathers.<ref name= TRJ1991>{{cite journal |last=McCullough|first=Elizabeth A.|title=Evaluation of Milkweed Floss as an Insulative Fill Material |journal=Textile Research Journal|date=April 1991 |volume=61 |issue=4 |pages=203–210|url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1009&context=textiles_facpub |doi=10.1177/004051759106100403}}</ref> Milkweed fibers are used to clean up oil spills.<ref>http://www.cbc.ca/news/politics/milkweed-touted-as-oil-spill-super-sucker-with-butterfly-benefits-1.2856029</ref>




Line 51: Line 49:
  ''[[Asclepias albicans]]'' || Whitestem milkweed, native to the [[Mojave Desert|Mojave]] and [[Sonora]]n deserts
  ''[[Asclepias albicans]]'' || Whitestem milkweed, native to the [[Mojave Desert|Mojave]] and [[Sonora]]n deserts
|-
|-
| [[File:Asclepias amplexicaulis Blue Ridge.jpg|120px]] || ''[[Asclepias amplexicaulis]]'' || Blunt-leaved milkweed, native to central and eastern [[United States]]
| ''[[Asclepias amplexicaulis]]'' || Blunt-leaved milkweed, native to central and eastern [[United States]]
|-
|-
| [[File:Asclepias asperula - Antelope Horns.jpg|120px]] || ''[[Asclepias asperula]]'' || [[Asclepias asperula|Antelope horns]], native to [[American southwest]] and northern [[Mexico]]
| ''[[Asclepias asperula]]'' || [[Asclepias asperula|Antelope horns]], native to [[American southwest]] and northern [[Mexico]]
|-
|-
| [[File:Asclepias sp. flowers (Marshal Hedin).jpg|120px]] || ''[[Asclepias californica]]'' || California milkweed, native to central and southern [[California]]
| ''[[Asclepias californica]]'' || California milkweed, native to central and southern [[California]]
|-
|-
| [[File:Asclepias cordifolia.JPG|120px]] || ''[[Asclepias cordifolia]]'' || [[Asclepias cordifolia|Heart-leaf milkweed]], native to the [[Sierra Nevada (U.S.)|Sierra Nevada]] and [[Cascade Range]] up to 2000&nbsp;m.
| ''[[Asclepias cordifolia]]'' || [[Asclepias cordifolia|Heart-leaf milkweed]], native to the [[Sierra Nevada (U.S.)|Sierra Nevada]] and [[Cascade Range]] up to 2000&nbsp;m.
|-
|-
| [[File:Asclepiascryptoceras.jpg|120px]] || ''[[Asclepias cryptoceras]]'' || Pallid milkweed, native to the western United States.
| ''[[Asclepias cryptoceras]]'' || Pallid milkweed, native to the western United States.
|-
|-
| [[File:Asclepias curassavica (Mexican Butterfly Weed) W IMG 1570.jpg|120px]] || ''[[Asclepias curassavica]]'' || Scarlet milkweed, tropical milkweed, bloodflower, bastard ipecacuanha, native to the American tropics, introduced to other continents
| ''[[Asclepias curassavica]]'' || Scarlet milkweed, tropical milkweed, bloodflower, bastard ipecacuanha, native to the American tropics, introduced to other continents
|-
|-
| [[File:Asclepias_curtissii_(Curtiss_milkweed_)_(5771618293).jpg|120px]] || ''[[Asclepias curtissii]]'' || Curtiss' milkweed, endemic to sandy areas of [[Florida]]
|   ''[[Asclepias curtissii]]'' || Curtiss' milkweed, endemic to sandy areas of [[Florida]]
|-
|-
| [[File:Asclepiaseriocarpa.jpg|120px]] || ''[[Asclepias eriocarpa]]'' || Woollypod milkweed, native to California, [[Baja California]], and [[Nevada]]
| ''[[Asclepias eriocarpa]]'' || Woollypod milkweed, native to California, [[Baja California]], and [[Nevada]]
|-
|-
| [[File:Asclepias erosa 5.jpg|120px]] || ''[[Asclepias erosa]]'' || Desert milkweed, native to California, [[Arizona]], and Baja California
| ''[[Asclepias erosa]]'' || Desert milkweed, native to California, [[Arizona]], and Baja California
|-
|-
| [[File:Asclepias exaltata (2985661678).jpg|120px]] || ''[[Asclepias exaltata]]'' || Poke milkweed, native to eastern [[North America]]
|   ''[[Asclepias exaltata]]'' || Poke milkweed, native to eastern [[North America]]
|-
|-
| [[File:Asclepias fascicularis flowers 2003-06-05.jpg|120px]] || ''[[Asclepias fascicularis]]'' || Narrow-leaf milkweed, native to [[Western United States]]
| ''[[Asclepias fascicularis]]'' || Narrow-leaf milkweed, native to [[Western United States]]
|-
|-
| [[File:Asclepias humistrata.jpg|120px]] || ''[[Asclepias humistrata]]'' || Sandhill milkweed, native to southeastern United States
| ''[[Asclepias humistrata]]'' || Sandhill milkweed, native to southeastern United States
|-
|-
| [[Image:Swamp Milkweed Asclepias incarnata Flowers Closeup 2800px.jpg|120px]] || ''[[Asclepias incarnata]]'' || Swamp milkweed, native to wetlands of North America
| ''[[Asclepias incarnata]]'' || Swamp milkweed, native to wetlands of North America
|-
|-
| [[File:Asclepias lanceolata plant.jpg|120px]] || ''[[Asclepias lanceolata]]'' || Lanceolate milkweed (Cedar Hill milkweed), native to coastal plain of eastern United States from [[Texas]] to [[New Jersey]]
| ''[[Asclepias lanceolata]]'' || Lanceolate milkweed (Cedar Hill milkweed), native to coastal plain of eastern United States from [[Texas]] to [[New Jersey]]
|-
|-
| [[File:Asclepias linaria.jpg|120px]] || ''[[Asclepias linaria]]'' || Pine needle milkweed, native to Mojave and Sonoran deserts
| ''[[Asclepias linaria]]'' || Pine needle milkweed, native to Mojave and Sonoran deserts
|-
|-
| || ''[[Asclepias linearis]]'' || Slim milkweed
| ''[[Asclepias linearis]]'' || Slim milkweed
|-
|-
| [[File:Asclepias longifolia.JPG|120px]] || ''[[Asclepias longifolia]]'' || Longleaf milkweed
| ''[[Asclepias longifolia]]'' || Longleaf milkweed
|-
|-
| [[File:Asclepiasmeadii.jpg|120px]] || ''[[Asclepias meadii]]'' || Mead's milkweed, native to midwestern United States
| ''[[Asclepias meadii]]'' || Mead's milkweed, native to midwestern United States
|-
|-
| [[File:Asclepias nyctaginifolia.jpg|120px]] || ''[[Asclepias nyctaginifolia]]'' || Mojave milkweed, native to the American southwest
| ''[[Asclepias nyctaginifolia]]'' || Mojave milkweed, native to the American southwest
|-
|-
| || ''[[Asclepias obovata]]'' || Pineland milkweed
| ''[[Asclepias obovata]]'' || Pineland milkweed
|-
|-
| [[File:Purple Milkweed Asclepias purpurascens Head.jpg|120px]] || ''[[Asclepias purpurascens]]'' || Purple milkweed, native to eastern, southern, and midwestern United States
| ''[[Asclepias purpurascens]]'' || Purple milkweed, native to eastern, southern, and midwestern United States
|-
|-
| [[File:Asclepias quadrifolia 001.jpg|120px]] || ''[[Asclepias quadrifolia]]'' || Four-leaved milkweed, native to eastern United States and [[Canada]]
| ''[[Asclepias quadrifolia]]'' || Four-leaved milkweed, native to eastern United States and [[Canada]]
|-
|-
| [[File:BB-3386 Asclepias rubra.png|120px]] || ''[[Asclepias rubra]]'' || Red milkweed
| ''[[Asclepias rubra]]'' || Red milkweed
|-
|-
|  [[File:Asclepias solanoana.jpeg|120px]] || ''[[Asclepias solanoana]]'' || Serpentine milkweed, native to [[northern California]]
|  ''[[Asclepias solanoana]]'' || Serpentine milkweed, native to [[northern California]]
|-
|-
| [[File:R27182818 milkweed img 0312.jpg|120px]] || ''[[Asclepias speciosa]]'' || Showy milkweed, native to western United States and Canada
| ''[[Asclepias speciosa]]'' || Showy milkweed, native to western United States and Canada
|-
|-
| [[File:Asclepias subulata flowers 2.jpg|120px]] || ''[[Asclepias subulata]]'' || Rush milkweed, leafless milkweed, native to southwestern North America
| ''[[Asclepias subulata]]'' || Rush milkweed, leafless milkweed, native to southwestern North America
|-
|-
| [[File:Asclepias subverticillata.jpg|120px]] || ''[[Asclepias subverticillata]]'' || Horsetail milkweed<ref>[http://plants.usda.gov/java/profile?symbol=ASSU2 Asclepias subverticillata (A. Gray) Vail], USDA PLANTS</ref>
|   ''[[Asclepias subverticillata]]'' || Horsetail milkweed<ref>[http://plants.usda.gov/java/profile?symbol=ASSU2 Asclepias subverticillata (A. Gray) Vail], USDA PLANTS</ref>
|-
|-
| [[File:Asclepias sullivantii.jpg|120px]] || ''[[Asclepias sullivantii]]'' || Sullivant's milkweed
| ''[[Asclepias sullivantii]]'' || Sullivant's milkweed
|-
|-
| [[File:Common milkweed-tracy.jpg|120px]] || ''[[Asclepias syriaca]]'' || Common milkweed
| ''[[Asclepias syriaca]]'' || Common milkweed
|-
|-
| [[File:Butterfly Weed Asclepias tuberosa Umbel.jpg|120px]] || ''[[Asclepias tuberosa]]'' || Butterfly weed, pleurisy root
| ''[[Asclepias tuberosa]]'' || Butterfly weed, pleurisy root
|-
|-
| [[File:Asclepias uncialis lg.jpg|120px]] || ''[[Asclepias uncialis]]'' || Wheel milkweed
| ''[[Asclepias uncialis]]'' || Wheel milkweed
|-
|-
| [[File:Asclepias variegata.jpg|120px]] || ''[[Asclepias variegata]]'' || White milkweed
| ''[[Asclepias variegata]]'' || White milkweed
|-
|-
| [[File:Asclepias verticillata (3197723098).jpg|120px]] || ''[[Asclepias verticillata]]'' || Whorled milkweed
| ''[[Asclepias verticillata]]'' || Whorled milkweed
|-
|-
| || ''[[Asclepias vestita]]'' || Woolly milkweed
| ''[[Asclepias vestita]]'' || Woolly milkweed
|-
|-
| [[File:Asclepias viridiflora NPS-1.jpg|120px]] || ''[[Asclepias viridiflora]]'' || Green milkweed
| ''[[Asclepias viridiflora]]'' || Green milkweed
|-
|-
| [[File:Asclepias viridis 1.jpg|120px]] || ''[[Asclepias viridis]]'' || Green antelopehorn, spider milkweed
|   ''[[Asclepias viridis]]'' || Green antelopehorn, spider milkweed
|-
|-
| [[File:Asclepias welshii 1.jpg|120px]] || ''[[Asclepias welshii]]'' || Welsh's milkweed
| ''[[Asclepias welshii]]'' || Welsh's milkweed
|-
|-
|}
|}
Line 131: Line 129:
Some species formerly classified under the ''Asclepias'' genus include:
Some species formerly classified under the ''Asclepias'' genus include:


* ''[[Calotropis gigantea]]'' <small>(L.) W.T.Aiton</small> (as ''A. gigantea'' <small>L.</small>)
* ''[[Calotropis gigantea]]'' (L.) W.T.Aiton (as ''A. gigantea'' L.)
* ''[[Calotropis procera]]'' <small>(Aiton) W.T.Aiton</small> (as ''A. procera'' <small>Aiton</small>)
* ''[[Calotropis procera]]'' (Aiton) W.T.Aiton (as ''A. procera'' Aiton)
* ''[[Cynanchum louiseae]]'' <small>Kartesz & Gandhi</small> (as ''A. nigra'' <small>L.</small>)
* ''[[Cynanchum louiseae]]'' Kartesz & Gandhi (as ''A. nigra'' L.)
* ''[[Cynanchum thesioides]]'' <small>(Freyn) K.Schum.</small> (as ''A. sibirica'' <small>L.</small>)
* ''[[Cynanchum thesioides]]'' (Freyn) K.Schum. (as ''A. sibirica'' L.)
* ''[[Funastrum clausum]]'' <small>(Jacq.) Schltr.<small> (as ''A. clausa'' <small>Jacq.</small>)
* ''[[Funastrum clausum]]'' (Jacq.) Schltr. (as ''A. clausa'' Jacq.)
* ''[[Gomphocarpus cancellatus]]'' <small>(Burm.f.) Bruyns</small> (as ''A. cancellatus'' <small>Burm.f.</small> or ''A. rotundifolia'' <small>Mill.</small>)
* ''[[Gomphocarpus cancellatus]]'' (Burm.f.) Bruyns (as ''A. cancellatus'' Burm.f. or ''A. rotundifolia'' Mill.)
* ''[[Gomphocarpus fruticosus]]'' <small>(L.) W.T.Aiton</small> (as ''A. fruticosa'' <small>L.</small>)
* ''[[Gomphocarpus fruticosus]]'' (L.) W.T.Aiton (as ''A. fruticosa'' L.)
* ''[[Marsdenia macrophylla]]'' <small>(Humb. & Bonpl. ex Willd.) E.Fourn.</small> (as ''A. macrophylla'' <small>Humb. & Bonpl. ex Schult.</small>)
* ''[[Marsdenia macrophylla]]'' (Humb. & Bonpl. ex Willd.) E.Fourn. (as ''A. macrophylla'' Humb. & Bonpl. ex Schult.)
* ''[[Marsdenia tenacissima]]'' <small>(Roxb.) Moon</small> (as ''A. tenacissima'' <small>Roxb.</small>)
* ''[[Marsdenia tenacissima]]'' (Roxb.) Moon (as ''A. tenacissima'' Roxb.)
* ''[[Matelea maritima]]'' <small>(Jacq.) Woodson</small> (as ''A. maritima'' <small>Jacq.</small>)
* ''[[Matelea maritima]]'' (Jacq.) Woodson (as ''A. maritima'' Jacq.)
* ''[[Sarcostemma acidum]]'' <small>(Roxb.) Voigt</small> (as ''A. acida'' <small>Roxb.</small>)
* ''[[Sarcostemma acidum]]'' (Roxb.) Voigt (as ''A. acida'' Roxb.)
* ''[[Sarcostemma viminale]]'' <small>(L.) R.Br.</small> (as ''A. viminalis'' <small>(L.) Steud.</small>)
* ''[[Sarcostemma viminale]]'' (L.) R.Br. (as ''A. viminalis'' (L.) Steud.)
* ''[[Telosma cordata]]'' <small>(Burm.f.) Merr.</small> (as ''A. cordata'' <small>Burm.f.</small>)
* ''[[Telosma cordata]]'' (Burm.f.) Merr. (as ''A. cordata'' Burm.f.)
* ''[[Telosma pallida]]'' <small>(Roxb.) Craib</small> (as ''A. pallida'' <small>Roxb.</small>)
* ''[[Telosma pallida]]'' (Roxb.) Craib (as ''A. pallida'' Roxb.)
* ''[[Tylophora indica]]'' <small>(Burm.f.) Merr.</small> (as ''A. asthmatica'' <small>L.f.</small>)
* ''[[Tylophora indica]]'' (Burm.f.) Merr. (as ''A. asthmatica'' L.f.)
* ''[[Vincetoxicum hirundinaria]]'' <small>Medik.</small> (as ''A. vincetoxicum'' <small>L.</small>)
* ''[[Vincetoxicum hirundinaria]]'' Medik. (as ''A. vincetoxicum'' L.)
* ''[[Vincetoxicum pycnostelma]]'' <small>Kitag.</small> (as ''A. paniculata'' <small>Bunge</small>)
* ''[[Vincetoxicum pycnostelma]]'' Kitag. (as ''A. paniculata'' Bunge)
* ''[[Xysmalobium undulatum]]'' <small>(L.) R.Br.</small> (as ''A. undulata'' <small>L.</small>)<ref name="GRINSpecies">{{Cite web |url=http://www.ars-grin.gov/cgi-bin/npgs/html/splist.pl?1031 |title=GRIN Species Records of ''Asclepias'' |work=Germplasm Resources Information Network |publisher=United States Department of Agriculture |accessdate=2011-02-22}}</ref>
* ''[[Xysmalobium undulatum]]'' (L.) R.Br. (as ''A. undulata'' L.)<ref name="GRINSpecies">{{Cite web |url=http://www.ars-grin.gov/cgi-bin/npgs/html/splist.pl?1031 |title=GRIN Species Records of ''Asclepias'' |work=Germplasm Resources Information Network |publisher=United States Department of Agriculture |accessdate=2011-02-22}}</ref>


== References ==
== References ==

Latest revision as of 14:39, 16 November 2015

WikiDoc Resources for Asclepias

Articles

Most recent articles on Asclepias

Most cited articles on Asclepias

Review articles on Asclepias

Articles on Asclepias in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Asclepias

Images of Asclepias

Photos of Asclepias

Podcasts & MP3s on Asclepias

Videos on Asclepias

Evidence Based Medicine

Cochrane Collaboration on Asclepias

Bandolier on Asclepias

TRIP on Asclepias

Clinical Trials

Ongoing Trials on Asclepias at Clinical Trials.gov

Trial results on Asclepias

Clinical Trials on Asclepias at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Asclepias

NICE Guidance on Asclepias

NHS PRODIGY Guidance

FDA on Asclepias

CDC on Asclepias

Books

Books on Asclepias

News

Asclepias in the news

Be alerted to news on Asclepias

News trends on Asclepias

Commentary

Blogs on Asclepias

Definitions

Definitions of Asclepias

Patient Resources / Community

Patient resources on Asclepias

Discussion groups on Asclepias

Patient Handouts on Asclepias

Directions to Hospitals Treating Asclepias

Risk calculators and risk factors for Asclepias

Healthcare Provider Resources

Symptoms of Asclepias

Causes & Risk Factors for Asclepias

Diagnostic studies for Asclepias

Treatment of Asclepias

Continuing Medical Education (CME)

CME Programs on Asclepias

International

Asclepias en Espanol

Asclepias en Francais

Business

Asclepias in the Marketplace

Patents on Asclepias

Experimental / Informatics

List of terms related to Asclepias

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Asclepias L. (1753), the milkweeds, is an American genus of herbaceous perennial, dicotyledonous plants that contains over 140 known species. It previously belonged to the family Asclepiadaceae, but this is now classified as the subfamily Asclepiadoideae of the dogbane family Apocynaceae.

Milkweed is named for its milky sap, which consists of a latex containing alkaloids and several other complex compounds including cardenolides.[1] Some species are known to be toxic.

Carl Linnaeus named the genus after Asclepius, the Greek god of healing.[2]

Milkweed flowers

Asclepias species produce some of the most complex flowers in the plant kingdom, comparable to orchids in complexity. Five petals reflex backwards revealing a gynostegium (fused stamen filamens and styles) surrounded by a five-membered corona. The corona is composed of a five paired hood and horn structures with the hood acting as a sheath for the inner horn. Glands holding pollinia are found between the hoods. The size, shape and color of the horns and hoods are often important identifying characteristics for species in the genus Asclepias.[3]

Pollination in this genus is accomplished in an unusual manner. Pollen is grouped into complex structures called pollinia (or "pollen sacs"), rather than being individual grains or tetrads, as is typical for most plants. The feet or mouthparts of flower-visiting insects such as bees, wasps and Butterfly|butterflies, slip into one of the five slits in each flower formed by adjacent anthers. The bases of the pollinia then mechanically attach to the insect, so that a pair of pollen sacs can be pulled free when the pollinator flies off, assuming the insect is large enough to produce the necessary pulling force (if not, the insect may become trapped and die).[4] Pollination is effected by the reverse procedure in which one of the pollinia becomes trapped within the anther slit.

Asclepias species produce their seeds in follicles. The seeds, which are arranged in overlapping rows, bear a cluster white, silky, filament-like hairs known as the coma[5] (often referred to by other names such as pappus, "floss", "plume", or "silk"). The follicles ripen and split open, and the seeds, each carried by its coma, are blown by the wind.


Ecology

American milkweeds are an important nectar source for native bees, wasps, and other nectar-seeking insects, though non-native honey bees commonly get trapped in the stigmatic slits and die,[4][6] and a larval food source for Monarch (butterfly)|monarch butterflies and their relatives, as well as a variety of other herbivorous insects (including numerous beetles, moths, and true bugs) specialized to feed on the plants despite their Plant defense against herbivory|chemical defenses.

Milkweeds use three primary defenses to limit damage caused by caterpillars: hairs on the leaves, cardenolide toxins, and latex fluids. Data from a DNA study indicate that more recently evolved milkweed species use these preventative strategies less but grow faster than older species, potentially regrowing faster than caterpillars can consume them.[7]

Uses

The milkweed filaments from the coma (the "floss") are hollow and coated with wax, and have good insulation qualities. During World War II, over of milkweed floss were collected in the United States as a substitute for kapok. As of 2007, milkweed is grown commercially as a hypoallergenic filling for pillows.[8] A study of the insulative properties of various materials found that milkweed floss was outperformed by other materials in insulation, loft, and lumpiness, but scored well on various metrics when mixed with down feathers.[9] Milkweed fibers are used to clean up oil spills.[10]


In the past, the high dextrose content of the nectar led to milkweed's use as a source of sweetener for Native Americans and voyageurs.

The bast fibers of some species can be used for cordage.

Milkweed latex contains about 1 to 2% latex, and was attempted as a source of natural rubber by both Germany and the United States during World War II. No record has been found of large-scale success.

Milkweed is beneficial to nearby plants, repelling some pests, especially wireworms.

Milkweed also contains cardiac glycoside poisons that inhibit animal cells from maintaining a proper K+, Ca+ concentration gradient.[citation needed] As a result, many natives of South America and Africa used arrows poisoned with these glycosides to fight and hunt more effectively. Milkweed is toxic and may cause death when animals consume 10% of their body weight in any part of the plant.[citation needed] Milkweed also causes mild dermatitis in some who come in contact with it.

The leaves of Asclepias species, and of some species formerly classified as Asclepias such as Gomphocarpus physocarpus, are the only food source for monarch butterfly larvae and other milkweed butterflies. These plants are therefore often used in butterfly gardening.[citation needed]

Species

Some Asclepias species:

Asclepias albicans || Whitestem milkweed, native to the Mojave and Sonoran deserts
Asclepias amplexicaulis Blunt-leaved milkweed, native to central and eastern United States
Asclepias asperula Antelope horns, native to American southwest and northern Mexico
Asclepias californica California milkweed, native to central and southern California
Asclepias cordifolia Heart-leaf milkweed, native to the Sierra Nevada and Cascade Range up to 2000 m.
Asclepias cryptoceras Pallid milkweed, native to the western United States.
Asclepias curassavica Scarlet milkweed, tropical milkweed, bloodflower, bastard ipecacuanha, native to the American tropics, introduced to other continents
Asclepias curtissii Curtiss' milkweed, endemic to sandy areas of Florida
Asclepias eriocarpa Woollypod milkweed, native to California, Baja California, and Nevada
Asclepias erosa Desert milkweed, native to California, Arizona, and Baja California
Asclepias exaltata Poke milkweed, native to eastern North America
Asclepias fascicularis Narrow-leaf milkweed, native to Western United States
Asclepias humistrata Sandhill milkweed, native to southeastern United States
Asclepias incarnata Swamp milkweed, native to wetlands of North America
Asclepias lanceolata Lanceolate milkweed (Cedar Hill milkweed), native to coastal plain of eastern United States from Texas to New Jersey
Asclepias linaria Pine needle milkweed, native to Mojave and Sonoran deserts
Asclepias linearis Slim milkweed
Asclepias longifolia Longleaf milkweed
Asclepias meadii Mead's milkweed, native to midwestern United States
Asclepias nyctaginifolia Mojave milkweed, native to the American southwest
Asclepias obovata Pineland milkweed
Asclepias purpurascens Purple milkweed, native to eastern, southern, and midwestern United States
Asclepias quadrifolia Four-leaved milkweed, native to eastern United States and Canada
Asclepias rubra Red milkweed
Asclepias solanoana Serpentine milkweed, native to northern California
Asclepias speciosa Showy milkweed, native to western United States and Canada
Asclepias subulata Rush milkweed, leafless milkweed, native to southwestern North America
Asclepias subverticillata Horsetail milkweed[11]
Asclepias sullivantii Sullivant's milkweed
Asclepias syriaca Common milkweed
Asclepias tuberosa Butterfly weed, pleurisy root
Asclepias uncialis Wheel milkweed
Asclepias variegata White milkweed
Asclepias verticillata Whorled milkweed
Asclepias vestita Woolly milkweed
Asclepias viridiflora Green milkweed
Asclepias viridis Green antelopehorn, spider milkweed
Asclepias welshii Welsh's milkweed

Formerly placed here

Some species formerly classified under the Asclepias genus include:

References

  1. ↑ Singh, B. and Rastogi, R.P. (1970). Cardenolides-glycosides and genins. Phytochemistry 9: 315-331.
  2. ↑ Quattrocchi, Umberto (29 November 1999). CRC World Dictionary of Plant Names: Common Names, Scientific Names, Eponyms, Synonyms, and Etymology. CRC Press. p. 211. ISBN 978-0-8493-2673-8. Latin asclepias and Greek asklepias for the common swallowwort; Asclepius, Greek god of medicine, the worship of Asclepius was centered in Epidaurus. See W.K.C. Guthrie, The Greeks and Their Gods, 1950; Carl Linnaeus, Species Plantarum. 214. 1753 and Genera Plantarum. Ed. 5. 102. 1754.
  3. ↑ http://orbisec.com/milkweed-flower-morphology-and-terminology/ Milkweed Flower Morphology
  4. ↑ 4.0 4.1 Robertson, C. (1887) Insect relations of certain asclepiads. I. Botanical Gazette 12: 207–216
  5. ↑ Sacchi, C.F. (1987) Variability in dispersal ability of Common Milkweed, Asclepias syriaca, seeds, Oikos Vol. 49, pp. 191-198
  6. ↑ Frost, S.W. (1965) Insects and pollinia. Ecology 46: 556–558
  7. ↑ Ramanujan, Krishna (Winter 2008). "Discoveries: Milkweed evolves to shrug off predation". Northern Woodlands. Center for Northern Woodlands Education. 15 (4): 56.
  8. ↑ Evangelista, R.L. (2007). "Milkweed seed wing removal to improve oil extraction". Industrial Crops and Products. 25 (2): 210–217. doi:10.1016/j.indcrop.2006.10.002.
  9. ↑ McCullough, Elizabeth A. (April 1991). "Evaluation of Milkweed Floss as an Insulative Fill Material". Textile Research Journal. 61 (4): 203–210. doi:10.1177/004051759106100403.
  10. ↑ http://www.cbc.ca/news/politics/milkweed-touted-as-oil-spill-super-sucker-with-butterfly-benefits-1.2856029
  11. ↑ Asclepias subverticillata (A. Gray) Vail, USDA PLANTS
  12. ↑ "GRIN Species Records of Asclepias". Germplasm Resources Information Network. United States Department of Agriculture. Retrieved 2011-02-22.
  • Everitt, J.H.; Lonard, R.L.; Little, C.R. (2007). Weeds in South Texas and Northern Mexico. Lubbock: Texas Tech University Press. ISBN 0-89672-614-2

External links

Template:Wikispecies

Retrieved from "https://www.wikidoc.org/index.php?title=Asclepias&oldid=1187190"