Tabernanthe Iboga.

Tabernanthe Iboga is a small shrub of the Apocynace family that grows principally in the equatorial forests of Gabon, Guinea, the Congo and the Cameroon.

The Mitsogho Bwiti of Gabon use the root for "rites de passage" ceremonies marking the transition from childhood to adulthood.
The Fang people of this region learned of the plant and made it a central part of their synchretic religion - Bwiti Fang. Consumuption of Iboga root is a central part of the Bwiti Fang initiation ritual. The Bwiti Fang religion is followed by the Pahouines people of Gabon, Guinea and the Cameroon.
Iboga is also used by in the Congo and Zaire as part of a healing ritual known as "Zebola".

Ibogaine.

IbogaÔne, an indole alkaloid found principally in the rootbark of the T. iboga plant, is now recognised for it's ability to interrupt dependence to cocaine, heroin and other opiates including methadone. This ability further extends, to varying degrees, to addictions to alcohol, tobacco and a variety of other substances.
The ability of Ibogaine to interrupt chemical dependence was first noted in the West by Howard Lotsof who for 30 years has battled to bring the drug and it's properties to public attention.
IbogaÔne is also recognised for it's use in the fields of psychology and psychiatry for it's ability to bring about regression into infancy.