Which South American plant's leaves are the natural source of cocaine, once used as a local anesthetic? Coca is the answer.
Coca refers chiefly to cultivated Erythroxylum species, especially Erythroxylum coca and Erythroxylum novogranatense. Indigenous Andean peoples have chewed coca leaves for thousands of years, using them to reduce fatigue, hunger, thirst, and altitude-related discomfort. The leaves contain cocaine and several other alkaloids, but chewing or drinking coca tea delivers them far more slowly and less intensely than purified cocaine.
Cocaine was first isolated from coca in the nineteenth century. By the late 1800s, physicians used it as a topical local anesthetic because it numbs tissue and constricts blood vessels. Its toxicity and dependence potential later encouraged the replacement of cocaine with safer synthetic anesthetics such as procaine and lidocaine.
A common mix-up is treating coca and cocaine as interchangeable names. Coca is the plant; cocaine is a concentrated alkaloid extracted from its leaves. Coca cultivation and leaf use remain traditional and regulated in parts of the Andes, while the purified drug is tightly controlled in most countries.