http://manu.montana.com/
Quote of one of the plants in the plant section: (is a new one to me.)
Mamperikipini, Fittonia sp. detail.
This species is employed by the Kofan and Siona-Secoya tribes of the Ecuadorian Amazon as a headache treatment. The Machiguenga know it as an hallucinogen, used in large amounts as part of the kamarampi mixture in previous generations before they gained knowledge of the use of Psychotria sp. for this purpose. They say that it produces visions of eyeballs.
(several other 'hallucinogenic' plants noted.)