- Locoweed is also a slang name for cannabis.
Oxytropis is the genus most commonly referred to as locoweed. The twenty-four species of Oxytropis contain a neurotoxin, swainsonine. Oxytropis is distributed throughout the western half of North American continent, particularly in the regions of the Great Plains and the Rocky Mountains. The varieties most frequently encountered by livestock are the white locoweed (Oxytropis sericea) and the purple locoweed (Oxytropis lambertii).
Effects on livestock
Locoweed is eaten during the early spring and late fall, when it is often the only green plant available to grazing animals. Ingestion causes symptoms similar to bovine spongiform encephalopathy (BSE), including erratic behavior, aggression, lethargy, depression, loss of balance, nervousness, and abortion, among others. Although symptoms reduce with time after removing the animal from exposure to locoweed, some nerve damage is permanent. In horses, this brain damage can make them dangerous to ride.
Locoweed takes its name from the Spanish loco, "crazy," referring to the behavior of animals which consume the herb.
- Subkingdom Tracheobionta