Editing Locoweed (section)

==Taxa producing swainsonine==
Swainsonine is produced by a small number of species, including species in several genera of plants and two genera of fungi.

[[File:Oxytropis sericea.jpg|thumb|''Oxytropis sericea'' in bloom]]
[[File:Astragalus lentiginosus 4.jpg|thumb|''Astragalus lentiginosus'' in fruit]]
[[File:Curtis's botanical magazine (No. 792) (8469881299).jpg|thumb|''Swainsona galegifolia'']]
''Oxytropis'' is distributed throughout western [[North America]], particularly in the [[Great Plains]] and [[Rocky Mountains]]. However, most species of ''Oxytropis'' have narrow habitat requirements and within those habitats are abundant only in unusually wet years.<ref name="RalphsJames1999">{{cite journal
|vauthors=Ralphs MH, James LF | title = Locoweed grazing
| journal = Journal of Natural Toxins
| volume = 8
| issue = 1
| pages = 47–51
|date=February 1999
| pmid = 10091127
}}</ref> The species most frequently encountered by livestock are ''[[Oxytropis lambertii|O. lambertii]]'' (Lambert locoweed, purple locoweed, woolly locoweed) and especially ''Oxytropis sericea'' (white locoweed, white point locoweed, white point loco). Swainsonine has also been found in ''[[Oxytropis campestris|O. campestris]]'' (in [[Canada]]).<ref name=Jonesetal1997p252/>

Some species of ''[[Astragalus (plant)|Astragalus]]'' (milkvetch) are also referred to as locoweed. Swainsonine has been found in:<ref name=Jonesetal1997p252/>
* ''[[Astragalus earlei|A. earlei]]'' (Big Bend loco)
* ''[[Astragalus mollissimus|A. mollissimus]]'' (purple woolly loco)
* ''[[Astragalus pubentissimus|A. pubentissimus]]'' (green river milkvetch)
* ''[[Astragalus lentiginosus|A. lentiginosis]]'' (spotted locoweed, freckled milkvetch)
* ''[[Astragalus wootoni|A. wootoni]]'' (garbancillo)
* ''[[Astragalus nothoxys|A. nothoxys]]'' (sheep milkvetch)
* ''[[Astragalus tephrodes|A. tephrodes]]'' (ashen milkvetch)
* ''[[Astragalus humistratus|A. humistratus]]'' (ground cover milkvetch)

In [[Argentina]], locoism (''locoismo'') was first reported in 2000. A flock of sheep grazing a pasture with ''[[Astragalus pehuenches]]'' was poisoned and 220 sheep (73%) died.<ref name=Roblesetal2000/> Although this was the first report of locoism in [[South America]],<ref name=Roblesetal2000/> swainsonine had been isolated previously from ''A. pehuenches'' and several other species in Argentina and [[Peru]].<ref name=Roblesetal2000/><ref name=Michael1997>{{cite journal
| author = Michael JP
| title = Indolizidine and quinolizidine alkaloids
| journal = Natural Product Reports
| volume = 14
| issue = 6
| pages = 619–36
|date=December 1997
| pmid = 9418297
| doi = 10.1039/NP9971400619 }}</ref>

In the [[Old World]], native plants causing locoism have not been reported. ''[[Astragalus lusitanicus]]'' in [[Morocco]] was suspected,<ref name="pmid9830691">{{cite journal
|vauthors=Abdennebi EH, el Ouazzani N, Lamnaouer D | title = Clinical and analytical studies of sheep dosed with various preparations of ''Astragalus lusitanicus''
| journal = Veterinary and Human Toxicology
| volume = 40
| issue = 6
| pages = 327–31
|date=December 1998
| pmid = 9830691
}}</ref> but has been shown be neither a producer of swainsonine nor an accumulator of selenium. Its toxicity is suspected to be due to a novel [[alkaloid]].<ref name="pmid10709444">{{cite journal
|vauthors=Ouazzani N, Lamnaouer D, Abdennebi EH | title = Toxicology of ''Astragalus lusitanicus'' Lam
| journal = Thérapie
| volume = 54
| issue = 6
| pages = 707–10
| year = 1999
| pmid = 10709444
}}</ref>

In [[Australia]], species of ''[[Swainsona]]'' (Darling pea) that cause pea struck include:<ref name=Jonesetal1997p252>[[#Jonesetal1997|Jones et al. (1997)]], page 752.</ref><ref>{{cite web
 |title       = Poisonous plant: Darling pea (''Swainsona'' spp.)
 |author      = Les Tanner
 |date        = August 2003
 |publisher   = Northern Inland Weeds Advisory Committee
 |url         = http://www.northwestweeds.nsw.gov.au/Poisonous%20plants%20label%20-%20darling%20pea.pdf
 |accessdate  = May 11, 2009
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20050615213946/http://northwestweeds.nsw.gov.au/Poisonous%20plants%20label%20-%20darling%20pea.pdf
 |archive-date = June 15, 2005
}}</ref>
* ''[[Swainsona luteola|S. luteola]]''
* ''[[Swainsona greyana|S. greyana]]'' (hairy Darling pea)
* ''[[Swainsona galegifolia|S. galegifolia]]'' (smooth Darling pea)

''Astragalus'' and ''Oxytropis'' are two of 20 genera (and 78 names of genera) in the tribe [[Galegeae]], subtribe Astragalinae. Some authorities include ''Swainsona'' in the subtribe.<ref>{{cite web
 |url         = http://www.ars-grin.gov/cgi-bin/npgs/html/gnlist.pl?1504
 |title       = GRIN Genera of Fabaceae subtribe Astragalinae
 |year        = 2003
 |accessdate  = May 12, 2009
 |publisher   = Germplasm Resources Information Network
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20081015234011/http://www.ars-grin.gov/cgi-bin/npgs/html/gnlist.pl?1504
 |archive-date = October 15, 2008
}}</ref> Formerly, ''Swainsona'' was in another subtribe, Coluteinae, that has been combined into Astragalinae.

Swainsonine has also been isolated from ''[[Sida carpinifolia]]'' and ''[[Ipomoea carnea]]'', and both species have been reported to cause locoism.<ref name="pmid12717675">{{cite journal
| author = Carod-Artal FJ
| title = [Neurological syndromes linked with the intake of plants and fungi containing a toxic component (I). Neurotoxic syndromes caused by the ingestion of plants, seeds and fruits]
| language = es| journal = Revista de Neurología
| volume = 36
| issue = 9
| pages = 860–71
| year = 2003
| pmid = 12717675
| url = http://www.revneurol.com/LinkOut/formMedLine.asp?Refer=2003018&Revista=Revneurol
| accessdate = May 13, 2009
}}</ref>

''[[Embellisia]]'', a [[fungus]] isolated from ''Oxytropis lambertii'', has also been shown to produce swainsonine and to cause locoism in rats.<ref name="pmid15309966">{{cite journal
 |vauthors   = McLain-Romero J, Creamer R, Zepeda H, Strickland J, Bell G
 |title      = The toxicosis of ''Embellisia'' fungi from locoweed (''Oxytropis lambertii'') is similar to locoweed toxicosis in rats
 |journal    = Journal of Animal Science
 |volume     = 82 | issue = 7 | pages = 2169–74
 |date       = July 2004
 |pmid       = 15309966 |doi = 10.2527/2004.8272169x }}</ref> ''[[Rhizoctonia leguminicola]]'', a fungal [[Plant pathology|plant pathogen]] that may occur on red clover (''[[Trifolium pratense]]''), also produces swainsonine. Although intoxication due to this fungus resembles locoism, it has additional signs and symptoms due to the production of other toxins.<ref name="pmid7665382">{{cite journal
 |vauthors=Croom WJ, Hagler WM, Froetschel MA, Johnson AD
 |title=The involvement of slaframine and swainsonine in slobbers syndrome: a review
 |journal=Journal of Animal Science  |volume=73  |issue=5  |pages=1499–1508  |date=May 1995  |pmid=7665382  |doi= 10.2527/1995.7351499x}}</ref>