coca (kō´kə), common name for shrubs of the genus Erythroxylum, particularly E. coca, of the family Erythroxylaceae, and found abundantly in upland regions and on mountain slopes of South America, as well as in Australia, India, and Africa. Certain South American peoples chew the leaves of one of several species mixed with an alkali, lime, which acts with saliva to release the drug cocaine from the leaves. In the low doses obtained in this way, the drug acts as a stimulant and an appetite depressant with physiological effects similar to those of tobacco. Coca leaves have been used for at least 8,000 years. Until the time of the Spanish conquest, only the Inca aristocracy was privileged to chew the coca leaves, but afterward, the Spanish encouraged the enslaved Native Americans all to use coca in order to get them to endure long periods of heavy labor and physical hardships. A cocaine-free extract of coca leaves is used in some soft drinks. Coca, a different plant than the cocoa plant cacao, is grown commercially in the N and central Andean countries and in Sri Lanka, Java, and Taiwan. Much coca is also grown in Andean countries for the illegal international drug trade. Coca is classified in the division Magnoliophyta, class Magnoliopsida, order Linales, family Erythroxylaceae.