West african shrub, used as a stimulant and entheogen by the Bwiti cult.
This entheogen is sacred to the syncretic Christian Bwiti cult of the Fang people of Gabon. It is also used at lower doses as a stimulant and aphrodisiac. Adherents to the cult believe use of eboka allows them to contact their ancestors. Initiation into the cult involves consuming large quantities of the drug (which in a few cases has lead to death), for the purposes of "breaking open the head".
Outside Africa, iboga extracts as well as the purified alkaloid ibogaine are used in treating opiate addiction. The therapy may last several days and upon completion the subject is generally no longer physically dependent.
No idea how to give an example for iboga >_<