The most valuable species, called C. Calisaya, is found in the forests of Caravaya in south Peru and in those of Bolivia.
Forest Products.-The forest and other natural products include rubber, cinchona bark, ivory-nuts, mocora and toquilla fibre for the manufacture of hats, hammocks, &c., cabaya fibre for shoes and cordage, vegetable wool (Bombax ceiba), sarsaparilla, vanilla, cochineal, cabinet woods, fruit, resins, &c. The original source of the Peruvian bark of commerce, the Cinchona calisaya, is completely exhausted, and the " red bark " derived from C. succirubra, is now the principal source of supply from Ecuador.
Quina or calisaya is a natural product of the eastern Andes, and is found at an altitude of 3000 to 9000 ft.
The calisaya trees of Bolivia rank among the best, and their bark forms an important item in her foreign trade.
For this reason those barks which, like C. Calisaya, C. officinalis, and C. Ledgeriana, contain but little colouring matter are preferred, the quinine being more easily extracted from them in a colourless form.
Until 1867 English manufacturers of quinine were entirely dependent upon South America for their supplies of cinchona bark, which were obtained exclusively from uncultivated trees, growing chiefly in Bolivia, Peru, and Ecuador, the principal species which were used for the purpose being Cinchona Calisaya; C. officinalis; C. macrocalyx, var.
Calisaya, known as the calisaya of Santa Fe, was strongly recommended for cultivation, because the shoots of felled trees afford bark containing a considerable amount of quinine; C. Pitayensia has been introduced into the Indian plantations on account of yielding the valuable alkaloid quinidine, as well as quinine.
Cinchona Calisaya has also been cultivated extensively in Bolivia and in Tolima, United States of Columbia.
The yield of quinine has been ascertained to increase annually until the eleventh year, at which it seems to reach its ' In Java, C. Calisaya, vars.
Angustifolia, crispa, Uritusinga and Bonplandiana, and to a lesser extent C. Calisaya, vars.
Howard pointed out that C. Pahudiana, and C. Calisaya, vars.
Southern Colombia, especially the eastern slopes of the Andes, produces another valuable tree, the Cinchona calisaya, from the bark of which quinine is made.