The fruit and leaves of Erythroxylum coca, the shrub from which cocaine is obtained. The use of coca leaves as a stimulating masticatory has been widespread among the people of the Amazon basin for many centuries. Cultivation was encouraged by Jesuit missionaries. A wad of dried leaves is chewed and formed into a small quid held against the cheek. The narcotic principle is the alkaloid cocaine, of which the leaves contain about 1 per cent. It acts directly on the central nervous system causing psychic exaltation and resistance to physical and mental fatigue. This plant was photographed growing on a farm in Ecuador near the Colombian border.