The following is a list of plants that, amazingly, affect the brains and mental states of the humans who ingest them.
Opium poppy (Papaver somniferum)
Peyote (Lophophora williamsii)
Salvia (Salvia divinorum)
Cannabis (Cannabis sativa)
Ayahuasca (Banisteriopsis caapi)
Betel nut (Areca catechu)
Tobacco (Nicotiana tabacum)