Cinchona ledgeriana" had a yield of 8 to 13 percent quinine in bark grown in Dutch Indonesia which effectively out-competed the British Indian production. It was only later that the English saw the value and sought to obtain the seeds of "C. ledgeriana" from the Dutch. During World War II, the Japanese conquered Java and the United States lost access to the cinchona plantations that supplied war-critical quinine medication. Botanical expeditions – called Cinchona Missions – were launched in 1942-1944 to explore promising areas of South America in an effort to locate cinchona species that contained quinine and could be harvested
Cinchona South America, the species had geographically distinct distributions. The introduction of several species into cultivation in the same areas in India and Java, respectively, by the English and Dutch East India Companies led to the formation of hybrids. Linnaeus described the genus based on the species "Cinchona officinalis." Nearly 300 species have been described and named in the genus but a revision of the genus in 1998 identified 23 distinct species. The febrifugal properties of bark from trees now known to be in the genus "Cinchona" were used by many South American cultures but malaria was an Old World disease