Ergot is a fungus that grows on rye and similar plants. The fungus produces an alkaloid that leads to a specific condition known as ergotism. Ergot alkaloids are very similar to LSD. Lysergic acid serves as the precursor to LSD, and plays a key role in the synthesis of this drug. Exposure to ergot alkaloids can lead to hallucinations and significant changes in overall behavior. Some of the other impacts of exposure to ergot alkaloids include uterine contractions, seizures, nausea, high fevers, and severe vomiting. The effects of this substance depend on the timing and degree of exposure.