Banisteriopsis caapi, also known as Ayahuasca, Caapi or Yage, is a South American jungle vine of the family Malpighiaceae. It is used to prepare ayahuasca, a decoction that has a long history of entheogenic uses as a medicine and "plant teacher" among the indigenous peoples of the Amazon Rainforest. It contains the beta-carboline harmala alkaloids and MAOIs harmine, harmaline, and tetrahydroharmine. The MAOIs in B. caapi allow the primary psychoactive compound, DMT (which is introduced from the other primary ingredient in ayahausca, the Psychotria viridis plant), to be orally active. The stems contain 0.11-0.83% beta-carbolines, with harmine and tetrahydroharmine as the major components..