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 people. Italian sources spelt Quina as Cina which was a source of confusion with "Smilax" from China. Haggis argued that Qina and Jesuit's bark actually referred to "Myroxylon peruiferum" or Peruvian balsam and that this was an item of importance in Spanish trade in the 1500s. Over time, the bark of the "Myroxylon" was adulterated with the similar looking bark of what we now know as "Cinchona". Gradually the adulterant became the main product that was the key therapeutic ingredient used in malarial therapy. The bark was included as "Cortex Peruanus" in the London Pharmacopoeia in 1677. The "fever tree"