Encyclopedia of the Incas

Chewed with potash or lime, coca leaves mitigate the effects of living and
working in the harsh Andean environment. The cultivation of this hardy bush
(genus Erythroxylum; family Erythroxylaceae) has a long history in Andean
South America; there is archaeological evidence for its use in Ecuador and the
north coast of Peru by 3000 BC (thus predating Inca civilization by over four
thousand years). The Incas considered coca essential to social and religious life;
sharing coca was a gesture of hospitality and regard. The host of a work party or
feast was expected to make liberal distributions of coca to those in attendance.
Since generous feast-giving was a prerequisite for high status and the ability to
mobilize labor, access to coca held political as well as economic significance
(see Feasts, State-Sponsored).
The Incas cultivated two varieties of coca. Small-leaved tupa coca (Trujillo
coca; Erythroxylum novogranatense var. truxillense) grows in the mid to high
river valleys of northern Peru and parts of Ecuador, thriving in arid, rocky soil,
300–1,800 meters (1,000–6,000 feet) in altitude. Larger-leaved mamas coca
(Huánuco or Bolivian coca; Erythroxylum coca var. coca) was cultivated along
the eastern Andean slopes in high forests, 500–2,000 meters (1,600–6,500 feet)
in altitude. Both varieties of coca contain under one percent by weight of the
alkaloid cocaine. Although mamas coca tends to have a higher cocaine content,
Inca nobility preferred the taste of tupa coca, which contains methyl salicylate
(wintergreen). When masticated with calcium carbonate (ashes or powdered
lime) to form a quid, the leaves are stimulating and temporarily suppress fatigue,
hunger, and thirst. Medicinal uses include the treatment of gastrointestinal
problems and high-altitude sickness. Because the leaves contain iron,
phosphorus, vitamin A, and riboflavin, coca has nutritional value as well.