Ergot is a fungus that grows on rye bread, and ingestion of too much ergot can lead to LSD-like hallucinations, seizures, episodes of mania, and even gangrene. In the Middle Ages, several ergot poisoning epidemics, and the resulting behaviors, led to witch hunts and exile. People in Europe referred to its effects as “St. Anthony’s Fire" in connection with the monks of the Order of St. Anthony, who were often successful at treating the ailment.