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How many flowering plants are there in the world?

One of the most challenging questions facing scientists is 'how many species are there in the world?'
A gallery of diversity

Previous estimates put the number of flowering plants between 223,000 and 422,000. Using expert analysis, scientists from Kew generated a more accurate estimate of 352,000 in a paper published in 2008. However, many flowering plant groups have yet to be assessed and the true number is likely to be just over 400,000. New plant species continue to be discovered, too, while others are under threat of extinction. Even changes in the way scientists classify plants alter the estimate, so the actual figure is in a constant state of flux.

The importance of understanding plants

Kew is a global centre for plant taxonomy - the science of naming and classifying plants. Kew’s scientists use this knowledge to help plant conservation worldwide.

Discovering and naming living organisms not only helps to answer the question 'how many plant species are there in the world?', it is also essential for habitat conservation, and for the effective use of plants for food, livelihoods and medicine. In 2010 Kew and Missouri Botanical Garden announced the release of The Plant List. This landmark international resource is a working list of all land plant species, a fundamental requirement for understanding and documenting plant diversity and for the effective conservation of plants.

Understanding plants in this way is important because every aspect of our lives depends on them. From the air we breathe and the clothes we wear to the untapped medicinal and food resources that lie undiscovered in the world’s plant species.

New discoveries


Sweet wormwood (Artmesia annua)
Sweet wormwood (Artemisia annua) is a sweetly aromatic herb, used in making anti-malarial drugs
Following in the footsteps of their famous predecessors such as Sir Joseph Hooker and Charles Darwin, scientists at Kew continue to explore and study the world’s plant and fungal diversity. On average they make 200 new discoveries every year, highlighting the fact that much of the plant world is still to be discovered.

Kew’s discoveries are not limited to our work in the field. Scientists in the laboratories at Kew go deeper in order to further understand plants and fungi. For example, we've identified plants that are used for controlling malaria, and plants that are used for treating people with HIV and diabetes.

The threats facing plants

We know that 22% of plant species already face the threat of extinction. Research also tells us that it is the impact of human actions and activity that poses the greatest threat to plant diversity today.

A global analysis of extinction risk for the world's plants conducted by Kew has revealed that the world’s plants are as threatened as mammals, with one in five of the world’s plant species threatened with extinction. In some areas and in certain groups of plants the figure is much higher. For example half of Madagascar’s 188 palm species were discovered by Kew experts in the last 20 years, and 90% of these are threatened with extinction.

Adopt a seed for just £25

For £25 you can adopt a seed in Kew's Millennium Seed Bank, or you can save an entire plant species from £1000.

Kew's Millennium Seed Bank Partnership has successfully banked 10% of the world's wild plant species and we have set our sights on saving 25% by 2020.

Without plants there could be no life on earth and yet every day another four plant species face extinction.

Help Kew protect the future of the world's plant life.