What is "locoweed"

n. Any of several plants indigenous to the western United States, of genus ''Oxytropis'' or ''Astragalus''.

1. n. any of several leguminous plants of western North America causing locoism in livestock [syn: crazyweed, crazy weed]

2. street names for marijuana [syn: pot, grass, green goddess, dope, weed, gage, sess, sens, smoke, skunk, Mary Jane]

Locoweed (also crazyweed and loco) is a common name in North America for any plant that produces swainsonine, a phytotoxin harmful to livestock. Worldwide, swainsonine is produced by a small number of species, most in three genera of the flowering plant family Fabaceae: Oxytropis and Astragalus in North America, and Swainsona in Australia. The term locoweed usually refers only to the North American species of Oxytropis and Astragalus, but this article includes the other species as well. Some references may list Datura stramonium as loco weed.

Locoweed is relatively palatable to livestock, and some individual animals will seek it out. Livestock poisoned by chronic ingestion of large amounts of swainsonine develop a medical condition known as locoism (also swainsonine disease, swainsonine toxicosis, locoweed disease, and loco disease; North America) and pea struck (Australia). Locoism is reported most often in cattle, sheep, and horses, but has been reported also in elk and deer. It is the most widespread poisonous plant problem in the western United States. Agricultural Research Service and New Mexico State University scientists have been collaborating since 1990 to help solve the problem that locoweed presents to livestock farmers. The research involved identifying the fungal species that produces the locoweed toxins, pinpointing levels of toxicity in animals once they have ingested locoweed, observing the effects of locoweed toxins on livestock’s reproduction and grazing preferences, etc. Together, the scientists assembled a grazing management scheme to help farmers avoid the poisonous locoweed.

Most of the 2000 species of Astragalus, including many that are commonly known as locoweeds, do not produce swainsonine. Some species, including a few that produce swainsonine, accumulate selenium. This has led to confusion between swainsonine poisoning and selenium poisoning due to this genus.

Locoweed (also loco-weed, loco weed, and capitalizations and plurals thereof) may refer to:

Plants

• Species in the genera Astragalus and Oxytropis, collectively
• Species in the genera Astragalus and Oxytropis, that cause locoism (locoweed disease) in livestock
• Species with "locoweed" (etc.) in a common name, including:

* Astragalus alpinus, mountain locoweed
* Astragalus austiniae, ball-flowered locoweed
* Astragalus canadensis, Canada locoweed
* Astragalus coccineus, scarlet locoweed
* Astragalus didymocarpus, white dwarf locoweed
* Astragalus gambelianus, dwarf locoweed
* Astragalus holmgreniorum, Holmgren locoweed
* Astragalus lentiginosus, mottled locoweed, speckled locoweed, spotted locoweed
* Astragalus mollissimus, woolly locoweed, stemmed locoweed
* Astragalus oxyphysus, Diablo locoweed
* Astragalus pomonensis, Pomona locoweed
* Astragalus purshii, woolly-pod locoweed
* Astragalus speirocarpus, coilpod locoweed
* Astragalus trichopodus, coast locoweed, Southern California locoweed
* Astragalus whitneyii, Whitney's locoweed * Cannabis, loco weed, when used as a recreational drug * Datura stramonium, loco weed, when used as a hallucinogen * Oxytropis arctica, arctic locoweed
* Oxytropis besseyi, Bessey's locoweed
* Oxytropis borealis, boreal locoweed
* Oxytropis campestris, Fassett's locoweed, field locoweed, northern yellow locoweed
* Oxytropis deflexa, nodding locoweed, pendant-pod locoweed
* Oxytropis huddelsonii, Huddelson's locoweed
* Oxytropis jordalii, Jordal's locoweed
* Oxytropis kobukensis, Kobuk locoweed
* Oxytropis kokrinensis, Kokrines locoweed
* Oxytropis lagopus, hare-foot locoweed
* Oxytropis lambertii, Colorado locoweed, Lambert locoweed, locoweed, purple locoweed, stemless locoweed, woolly locoweed
* Oxytropis maydelliana, Maydell's locoweed

:* Oxytropis mertensiana, Mertens' locoweed

* Oxytropis monticola, late yellow locoweed, yellow-flower locoweed
* Oxytropis multiceps, southwestern locoweed
* Oxytropis nana, Wyoming locoweed
* Oxytropis nigrescens, black(ish) locoweed
* Oxytropis oreophila, mountain locoweed
* Oxytropis parryi, Parry's locoweed
* Oxytropis podocarpa, stalked-pod locoweed
* Oxytropis riparia, Ruby Valley locoweed
* Oxytropis scammaniana, Scamman's locoweed
* Oxytropis sericea, early yellow locoweed, locoweed, Rocky Mountain locoweed, silky locoweed, white locoweed, white point locoweed
* Oxytropis splendens, showy locoweed, whorled locoweed
* Oxytropis viscida, sticky locoweed Music

• Loco Weed, Mel Tillis song