regions. Among the more important
productions, the potato, oca (_Oxalis tuberosa_), quinoa (_Chenopodium
quinoa_) and some coarse grasses characterize the puna region, while
barley, an exotic, is widely grown for fodder. Indian corn was
cultivated in the temperate and warm regions long before the advent of
Europeans, who introduced wheat, rye, oats, beans, pease and the fruits
and vegetables of the Old World, for each of which a favourable soil and
climate was easily found. In the sub-tropical and tropical zones the
indigenous plants are the sweet potato, cassava (_Manihot utilissima_
and _M. aipi_), peanuts, pineapple, guava, chirimoya (_Anona
cherimolia_), pawpaw (_Carica papaya_), _ipecacuanha_ (_Cephaelis_),
sarsaparilla, vanilla, false jalap (_Mirabilis jalapa_), copaiba, tolu
(_Myroxylon toluiferum_), rubber-producing trees, dyewoods, cotton and
a great number of beautiful hardwoods, such as jacaranda, mahogany,
rosewood, quebracho, colo, cedar, walnut, &c. Among the fruits many of
the most common are exotics, as the orange, lemon, lime, fig, date,
grape, &c., while others, as the banana, caju or cashew (_Anacardium
occidentale_) and aguacate avocado or alligator pear, have a disputed
origin. Coca, one of the most important plants of the country, is
cultivated on the eastern slopes of the Andes at an altitude of 5000 to
6000 ft., where the temperature is uniform and frosts are unknown. Quina
or calisaya is a natural product of the eastern Andes, and is found at
an altitude of 3000 to 9000 ft. above sea-level. The calisaya trees of
Bolivia rank among the best, and their bark forms an important item in
her foreign trade. The destructive methods of collecting the bark are
steadily diminishing the natural sources of supply, and experiments in
cinchona cultivation were undertaken during the last quarter of the 19th
century, with fair prospects of success. The most important of the
indigenous forest products, however, is rubber, derived principally from
the _Hevea guayanensis_ (var. _brasiliensis_), growing along the river
courses in the _yungas_ regions of the north, though Manicoba rubber is
also obtained from _Manihot Glaziovii_ on the drier uplands. Among the
exotics, sugar-cane, rice and tobacco are cultivated in the warm
districts.

_Population._--The population of Bolivia is composed of Indians,
Caucasians of European origin, and a mixture of the two races, generally
described as _mestizos_. There is also a very