Cinchona is a genus of flowering plants in the family Rubiaceae containing at least 23 species of trees and shrubs. They are native to the tropical Andean forests of western South America. A few species are reportedly naturalized in Central America, Jamaica, French Polynesia, Sulawesi, Saint Helena in the South Atlantic, and São Tome & Principe off the coast of tropical Africa. A few species are used as medicinal plants, known as sources for quinine and other compounds. The National Tree of Peru is in the genus Cinchona.