Scientists from around the world agree that there are roughly 400,000 flowering plant species in the world today. At one time, they thought there were closer to one million flower species, but most were deleted because they were duplicates.
In 2010, botanists from the United States, the United Kingdom and other countries began counting the number of flowering plants that have been identified. Scientists have been identifying and classifying flowers for centuries and during that time, many have been named more than once, because many scientists didn't realize the plants had already been named. During this process, many plants were added or removed from the list of endangered plants, or those faced with the possibility of going extinct.