IT IS A wet evening deep in the Amazon rainforest when members of the Koreguaje, a tribe of indigenous Colombians, line up to receive brews of ayahuasca, a hallucinogenic potion made from vines. They are handed out by taitas, or shamans, who have travelled in by boat along a river to reach the jungle. As the brew kicks in, the participants’ stomachs rumble—diarrhoea and vomiting are the vine’s other main effects. The taitas play a harmonica tune as some people go outside in search of relief; others lie back in their hammocks. The ceremony ends with the taitas singing to participants and patting their backs with dried leaves. At dawn, the ground around the shack is littered with used toilet paper.
For centuries ayahuasca has been taken in ceremonies like this one by several tribes inhabiting the Amazon region. In Colombia, consuming the brew is as much a political symbol as a cultural rite. Under the country’s constitution, indigenous groups, who have long been persecuted by cocaine smugglers and others, are entitled to special rights such as collective land ownership and self-governance. But given that most people in Colombia have some Amerindian ancestry, claiming that status is difficult. Because ayahuasca has been used by these tribes since before the Spanish arrived in the 16th century, it is one of the few ways in which indigenous groups can prove to the government that they are culturally distinct. Tribe members have testified in court to its importance.