Every now and then the Amahuaca hold seances in order to interact with yos hi in greater numbers and for a longer time than they usually do in dreams. While many Amazonian tribes rely on tobacco narcosis to achieve spirit visions, the Amahuaca do not. They make use instead of an infusion made from the narcotic plant ayahuasca! (Banisteriopsis caapi), which has the power to produce extremely vivid and colorful hallucinations. To make the potion, sections of the ayahuasca vine, which grows wild in the forest, are first pounded and then boiled in water for about an hour. Sometimes one or two other plants may be added to increase its effectiveness. In any case, the stronger the potion the more yoshi one will see.