I was curious what kind of hallucinogen it was, it appears to be from Rhododendron pollen as well as a few other relatives:

Slowing of heart rate and lowering of blood pressure are typical effects reported in one review of cases.[5] Dizziness, nausea, fainting, and weakness were reported as common neurological outcomes.[3][5][11] Other early-onset symptoms may include doubled and blurred vision, hypersalivation, perspiration, and paresthesia in the extremities and around the mouth. In higher doses, symptoms can include loss of coordination, severe and progressive muscular weakness