Iboga
Tabernanthe iboga or simply iboga is a perennial rainforest shrub, native to western Central Africa. Iboga can be used as a drug; it stimulates the central nervous system when taken in small doses and induces hallucinations in larger doses.  In parts of Africa where the plant grows, the bark of the root is chewed for various pharmacological or ritualistic purposes.  Ibogaine, the active alkaloid, is also used to treat substance abuse disorders and depression. A small amount of ibogaine, along with precursors of ibogaine, are found in Voacanga africana.