Coca
Coca refers to any of the four cultivated plants in the family Erythroxylaceae, native to western South America. It is known worldwide for its psychoactive alkaloid, cocaine. The leaves contain cocaine, which acts as a mild stimulant when chewed or consumed as tea; this traditional use involves slower absorption than purified cocaine, and there is no evidence of addiction or withdrawal symptoms from such natural consumption.
The coca plant is a shrub-like bush with curved branches, oval leaves marked by distinct curved lines, and small yellowish-white flowers that develop into red berries. Genomic analysis indicates coca was domesticated two or three separate times from the wild species Erythroxylum gracilipes by different South American groups during the Holocene. Chewing coca leaves dates back at least 8,000 years in South America, as evidenced by coca leaves and calcite found in house floors in Peru's Nanchoc Valley, suggesting early communal use alongside the rise of farming. Coca use was widespread under Inca rule. The Incas deeply integrated it into their society for labor, religion, and trade, valuing it so highly that they colonized new lands for its cultivation. Although Spanish colonizers later attempted to suppress its use, they ultimately relied on it to sustain enslaved laborers. Traditionally, across Andean cultures, coca leaves have been used for medicinal, nutritional, religious, and social purposes—serving as a stimulant, remedy for ailments, spiritual tool, and source of sustenance, primarily through chewing and tea.
Coca thrives in hot, humid environments and can be harvested multiple times a year from carefully tended plots. It is grown as a cash crop in the Argentine Northwest, Bolivia, the Alto Rio Negro Indigenous Territory in Brazil, Colombia, Venezuela, Ecuador, and Peru, including in areas where its cultivation is unlawful. There are some reports of cultivation in southern Mexico using seeds imported from South America, as an alternative to smuggling the processed drug cocaine. The plant plays a fundamental role in many traditional Amazonian and Andean cultures, as well as among indigenous groups in the Sierra Nevada de Santa Marta of northern Colombia.
Coca leaves are used commercially and industrially in teas, foods, cosmetics, and beverages. Their legal commercial use has growing political and market support in countries like Bolivia and Peru, despite restrictions in others like Colombia. The international prohibition of the coca leaf, established by the 1961 United Nations Single Convention—which did not distinguish it from cocaine despite traditional Andean uses—has been widely contested. Bolivia and Peru have led ongoing efforts to reevaluate its status, including a scheduled 2025 WHO review based on cultural and scientific grounds. Outside South America, coca leaf is generally illegal or heavily restricted, often treated similarly to cocaine. Limited exceptions exist for scientific or medical use, and for specific authorized imports such as the decocainized leaf extract used for Coca-Cola flavoring in the United States.
The cocaine alkaloid content in dry Erythroxylum coca var. coca leaves ranges from 0.23% to 0.96%. Coca-Cola used coca leaf extract in its products from 1885 until about 1903, when it switched to using a decocainized leaf extract. Extracting cocaine from coca requires several solvents and a chemical process known as an acid–base extraction, which can efficiently isolate the alkaloids from the plant material.
Description
The coca plant resembles a blackthorn bush, and grows to a height of. The branches are curved, and the leaves are thin, opaque, oval, and taper at the extremities. A marked characteristic of the leaf is an areolated portion bounded by two longitudinal curved lines, one line on each side of the midrib, and more conspicuous on the under face of the leaf.The flowers are small, and disposed in clusters on short stalks; the corolla is composed of five yellowish-white petals, the anthers are heart-shaped, and the pistil consists of three carpels united to form a three-chambered ovary. The flowers mature into red berries.
The leaves are sometimes eaten by the larvae of the moth Eloria noyesi.
Species and evolution
There are two species of coca crops, each with two varieties:- Erythroxylum coca
- *Erythroxylum coca var. coca – well adapted to the eastern Andes of Peru and Bolivia, an area of humid, tropical, montane forest.
- *Erythroxylum coca var. ipadu – cultivated in the lowland Amazon Basin in Peru and Colombia.
- Erythroxylum novogranatense
- *Erythroxylum novogranatense var. novogranatense – a highland variety that is utilized in lowland areas. It is cultivated in drier regions found in Colombia. However, E. novogranatense is very adaptable to varying ecological conditions. The leaves have parallel lines on either side of the central vein. These plants are called "Hayo" or "Ayu" among certain groups in Venezuela and Colombia.
- *Erythroxylum novogranatense var. truxillense – grown primarily in the Cajamarca and Amazonas states in Peru, including for the . and export by Coca-Cola for beverage flavoring.
An initial theory of the origin and evolution of the cocas by Plowman and Bohm suggested that Erythroxylum coca var. coca is ancestral, while Erythroxylum novogranatense var. truxillense is derived from it to be drought tolerant, and Erythroxylum novogranatense var. novogranatense was further derived from Erythroxylum novogranatense var. truxillense in a linear series. In addition, E. coca var. ipadu was separately derived from E. coca var. coca when plants were taken into the Amazon basin.
Genetic evidence does not support this linear evolution. None of the four coca varieties are found in the wild, despite prior speculation by Plowman that wild populations of E. coca var. coca occur in the Huánuco and San Martín provinces of Peru. Recent phylogenetic evidence shows the closest wild relatives of the coca crops are Erythroxylum gracilipes and Erythroxylum cataractarum, and dense sampling of these species along with the coca crops from throughout their geographic ranges supports independent origins of domestication of Erythroxylum novogranatense and Erythroxylum coca from ancestor Erythroxylum gracilipes. It is possible that Amazonian coca was produced by yet a third independent domestication event from Erythroxylum gracilipes.
Thus, different early-Holocene peoples in different areas of South America independently transformed Erythroxylum gracilipes plants into quotidian stimulant and medicinal crops now collectively called coca.
Herbicide-resistant varieties
Also known as supercoca or la millionaria, Boliviana negra is a relatively new form of coca that is resistant to a herbicide called glyphosate. Glyphosate is a key ingredient in the multibillion-dollar aerial coca eradication campaign undertaken by the government of Colombia with U.S. financial and military backing known as Plan Colombia.The herbicide resistance of this strain has at least two possible explanations: that a "peer-to-peer" network of coca farmers used selective breeding to enhance this trait through tireless effort, or the plant was genetically modified in a laboratory. In 1996, a patented glyphosate-resistant soybean was marketed by Monsanto Company, suggesting that it would be possible to genetically modify coca in an analogous manner. Spraying Boliviana negra with glyphosate would serve to strengthen its growth by eliminating the non-resistant weeds surrounding it. Joshua Davis, in the Wired article cited below, found no evidence of CP4 EPSPS, a protein produced by the glyphosate-resistant soybean, suggesting Bolivana negra was either created in a lab by a different technique or bred in the field.
Distribution and habitat
The seeds are sown from December to January in small plots sheltered from the sun, and the young plants when at in height are placed in final planting holes, or if the ground is level, in furrows in carefully weeded soil. The plants thrive best in hot, damp and humid locations, such as the clearings of forests; but the leaves most preferred are obtained in drier areas, on the hillsides. The leaves are gathered from plants varying in age from one and a half to upwards of forty years, but only the new fresh growth is harvested. They are considered ready for plucking when they break on being bent. The first and most abundant harvest is in March after the rainy season, the second is at the end of June, and the third in October or November. The green leaves are spread in thin layers on coarse woollen cloths and dried in the sun; they are then packed in sacks, which must be kept dry in order to preserve the quality of the leaves.Regions
According to a 2006 report by the United Nations Office on Drugs and Crime, coca plants grow best in the humid, tropical climates and specific altitudes found in the [|Andean regions] of South America, particularly in Bolivia, Colombia, and Peru, which together account for the vast majority of global coca cultivation—and produce 99% of all cocaine worldwide.As of 2023, coca cultivation has also rapidly expanded into northern Central America, in the highland areas of Honduras, Guatemala, and Belize.
While regions like Taiwan and Java were prominent centers of coca leaf cultivation in Asia before World War II, their climates and soils remain highly suitable for large-scale coca production today. This historical precedent suggests that, if demand or policy ever shifted, these areas could once again support thriving coca plantations. These examples highlight that, despite their current historical status, such regions retain the biophysical capacity for renewed coca production on a significant scale.