PhysOrg: There are more different kinds of trees in the Amazon rainforest than anywhere else on earth, but the exact number has long been a mystery. In 2013, scientists estimated that the number of species was around 16,000no one had ever counted them all up, though. In a new paper in Scientific Reports, the same scientists delved into museum collections from around the world to confirm just how many tree species have been recorded in the Amazon so farand how many have yet to be discovered. Nigel Pitman,...