Editing Locoweed (section)

==History and etymology==
The first technical account (in [[English language|English]]) of locoism was published in 1873, in the United States. [[Linguist]]s have documented ''locoism'' in use among English speakers by 1889, and both ''loco'' and ''locoweed'' in use by 1844.<ref name=SmeadSlatta2004>{{cite book
|title=Vocabulario Vaquero/cowboy Talk: A Dictionary Of Spanish Terms From The American West
|author1=Robert N. Smead  |author2=Richard W. Slatta
 |publisher=University of Oklahoma Press
|year=2004
|isbn=978-0-8061-3631-8
|pages=197
|url=https://books.google.com/books?id=MR4SY5n3_L8C
}} page 115</ref>

''Loco'', a [[loanword]] from [[Spanish language|Spanish]], is understood by most English-speaking users in the sense of ''crazy'', and this appears to have also been the sense understood by [[vaquero]]s.<ref name=SmeadSlatta2004/> In Spanish, however, ''loco'' has an older, different sense. In [[Spain]], where the native ''Astragalus'' species are not known to cause locoism, for centuries ''loco'' has been applied to some of these species in the sense of ''rambling'': common names include ''yerba loca'' (''hierba loca''; rambling herb) and ''chocho loco'' (rambling lupine).{{cn|date=October 2023}}

The presence of a toxin in locoweed was demonstrated in 1909. Initially, the toxin was reported to be a [[barium]] compound, but that was soon disproved. Swainsonine, first isolated from ''Swainsona'', was shown to be responsible for pea struck in 1979, and was reported in both ''Oxytropis'' and ''Astragalus'' in 1982.<ref name=KeelerTu1983p454>[[#KeelerTu1983|Keeler and Tu (1983)]], page 454.</ref>

Since 1982, swainsonine has been isolated from still more plants, some of which also are reported to cause locoism or medical conditions similar to it. The first report of locoism in [[South America]], involving ''Astragalus pehuenches'', was published in 2000.<ref name=Roblesetal2000>{{cite journal
|title=Intoxicación por ''Astragalus pehuenches'' (locoismo) en ovinos Merino de la Patagonia Argentina
|trans-title=''Astragalus pehuenches'' (locoweed) poisoning in a Merino sheep flock in Patagonia Region, Argentina
|year=2000
|author1=C.A. Robles
|author2=C. Saber
|author3=M. Jefrey
|journal=Revista de Medicina Veterinaria
|volume=81
|issue=5
|pages=380–384
|url=http://www.provino.com.ar/salud-animal-s/232-intoxicacion-por-astragalus-pehuenches-locoismo-en-ovinos-merino-de-la-patagonia-argentina
|access-date=March 2, 2017
|archive-date=March 3, 2017
|archive-url=https://web.archive.org/web/20170303051622/http://www.provino.com.ar/salud-animal-s/232-intoxicacion-por-astragalus-pehuenches-locoismo-en-ovinos-merino-de-la-patagonia-argentina
|url-status=dead
}}</ref>