a genus of evergreen tree of the family Rubiaceae. The trees are 10–15 m tall (some up to 25 m). The leaves are opposite, leathery, and entire. The pentamerous, tubular flowers are in cymose umbels, gathered into panicles. The corolla is pink or yellowish white and has lobes that are pubescent on the limb. The fruit is a dehiscent, bilocular, many-seeded, elongate capsule.
There are about 40 species, distributed in South America between 10° N lat. and 19° S lat. The trees grow at elevations of 1,600–2,400 m above sea level in forests on the eastern slopes of the Andes (C. officinalis is found at elevations to 3,300 m above sea level). The bark and other parts of the cinchona tree contain quinine, cinchonine, and other alkaloids that have antimalarial, tonic, and antiseptic effects. Since the 17th century, the tree has been greatly exploited for the healing properties of its bark. Despite a ban on export, Europeans sent cinchona seeds and seedlings to Java and India, where plantations were established. As a result of selection, the alkaloid content in the bark was raised from 2–2.5 percent to 16 percent. Several species, including C. ledgeriana, C. officinalis, and C. succirubra, and numerous hybrid forms are cultivated. In the USSR the cinchona tree is cultivated as an annual crop on the Black Sea coast of the Caucasus; cuttings and ovaries are preserved for the winter in hothouses. Cinchona culture is being curtailed as a result of the synthetic manufacture of its alkaloids.
S. S. MORSHCHIKHINA