As of 2010, there were approximately 400,000 types of flowering plant species in the world, according to The Guardian. More than 600,000 plant names were deleted due to discoveries of duplicate species upon further examination by botanists, The Guardian says.
The repeat 600,000 plant names were a result of monikers and subtle differences within one plant species, according to Phys.org. For example, the tomato had 760 different names. In 2002, 193 members at the Convention on Biological Diversity decided to compile all of the lists of plant species to create one master list. This was a three-year endeavor, according to Phys.org.