Thief at the End of the World by Joe Jackson
Jackson's loose biography of Henry Wickham, who studied the various rubber trees of the world and wrote the book on cultivating hevea brasiliensis. The empire-minded chaps at Kew Business & Botanicals forwarded some seeds of his cultivar to Ceylon, helping the colonies increase their production value.
When rust destroyed the coffee plantations of Malaya, rubber came to their rescue. It's not clear why Wickham didn't buy a dying coffee plantation for cheap and plant hevea; perhaps all his prior failures in the backwoods of Brazil and New Guinea had dimmed his eyes. Too early he was, then....In 1859, the London journals began to chronicle Britain's two-year quest to smuggle cinchona from the Andes...
When cascarillos felled cinchona during collection, they pulled up young trees with no thought of replanting or conservation. The world's only defense against malaria might go the way of the dodo. Theft in such a case would be a humanitarian act...
Left unsaid was the fact that malaria's defeat would end the deathwatch of the "white man's grave" and leave the tropics open for colonization.
They found the jungle no longer transcendent but claustrophobic, a parasite world of shadows and green. It was "a places of terror and death," filled with savagery.(stuff kills you back home, too; it's just that you know how to deal with it.)
Jungle tales almost always dwell on this savagery.