Additional Common Names:
fall poison, richweed, tremetol
Found in the eastern and southern U.S., westward from Minnesota to Texas in open wooded or semi-shaded areas.
Plant is toxic year round, although poisonings typically occur in summer and late fall. Horses eating one to ten percent of their body weight in the plant can develop lethal clinical effects. Onset of signs generally occurs after two days to three weeks of ingestion, and includes incoordination, muscle weakness and tremors, elevated heart rate, cardiac arrhythmias, profuse sweating, inability to swallow. The toxin is also passed in mare's milk; nursing foals can develop clinical signs as a result.
Toxic to Horses