9,200 tree species still undiscovered

Researchers estimate there are significantly more species of trees on Earth than currently known, with more than 9,200 species yet to be discovered, according to a study published Monday. About 64,100 tree species have already been identified. According to the study the total number of tree species is about 73,300 -- 14 percent more. Overall, the study said that "roughly" 43 percent of all tree species are found in South America, followed by Eurasia (22 percent), Africa (16 percent), North America (15 percent) and Oceania (11 percent).