A very well researched and informative study from the Transnational Institute about the Coca (erythroxylum) plant.
Coca leaf divination with Doris Rivera Lenz (Cuzco)
Mama Coca presenting the 'Divine Plant' to the Old World
Coca Leaves
The Huitoto people use coca as part of the social and ceremonial traditions. Here is Mariano the shaman with a coca bush.
Ofrenda Ceremony in the Andes, Curandera Doris Rivera Lenz with coca leaves.