In a sacred landscape in which every plant is a manifestation of the divine, the chewing of hayo, a variety of coca only found in the mountains of Colombia, represents the most profound expression of culture. Distance in the mountains is not measured in miles but coca chews. When two men meet, they do not shake hands, they exchange leaves. Their societal ideal is to abstain from sex, eating and sleeping while staying up all night, chewing hayo and chanting the names of ancestors. Each week the men chew about a pound of dry leaves, thus absorbing as much as a third of a gram of cocaine each day of their adults lives.
-- Wade Davis, One River