Cinchona
Cinchona, genus of tropical evergreen trees and shrubs of the madder family, yielding the medicinal bark variously known as Peruvian bark, Jesuits' bark, China bark, or cinchona bark, from which the drug quinine and related substances are obtained. All the cinchonas have laurel-like, entire, opposite leaves; stipules that soon fall off; and panicles of flowers that somewhat resemble those of the lilac. The flowers are white, rose, or purplish and very fragrant. Scientific classification: Cinchonas belong to the family Rubiaceae. The species first discovered is classified as Cinchona officinalis. The important species found in Bolivia and southeastern Peru is classified as Cinchona calisaya, the species in Peru and Ecuador as Cinchona succirubra.