BOTANICAL MUSEUM LEAFLETS 
HARVARD UNIVERSITY 
CAMBRIDGE, MAssAcHUSETTS, JUNE 30, 1960 VoL. 19, No. 5 
PRESTONIA: AN AMAZON NARCOTIC 
OR NOT? 
BY 
Ricuarp Evans SCHULTES AND Rospert F. Rarraur 
i. 
THrovuGcuHout the literature concerning native narcotic 
plants of South America may be found the statement 
that Prestonia amazonica (Haemadyction amazonicum), 
an apocynaceous vine, is the basic ingredient in the hal- 
lucinogen known as yaje. But many specialists, including 
most field investigators, have attributed yaje to sundry 
species of the malpighiaceous genus Banisteriopsis. They 
have been in essential agreement that yaye (of the west- 
ernmost Amazon of Colombia, Ecuador and a part of 
Peru, especially along the eastern slope of the Andes), 
ayahuasca (of Peru, Bolivia and part of Ecuador) and 
caapi (of the northwestern Amazon of Brazil and adja- 
cent parts of Colombia) seem to be identical narcotics 
prepared from malpighiaceous plants. 
That a member of the Apocynaceae might be em- 
ployed in the Amazon as the source of a psychotomim- 
etic drink is vitally important and would not appear to 
be an improbability. It was for this reason that Schultes 
(28), in 1957, reviewed the history of reports concerning 
Prestonia amazonica, keeping a sharp outlook for any 
well documented and botanically supported record. He 
concluded that while Prestonia amazonica is frequently 
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