One in five of the world’s plant species are estimated to be threatened with extinction, according to the State of the World’s Plants released on Monday by experts at the Royal Botanic Gardens Kew. The biggest factors threatening plant species is the destruction of habitats, including for farming, but the report also reveals that there are 2000 new plant species discovered each year. “This is the first ever global assessment on the state of the world’s plants,” said Professor Kathy Willis, Director of Science at the Royal Botanic Gardens, Kew. “We already have a ‘State of the World’s …birds, sea-turtles, forests, cities, mothers, fathers, children even antibiotics’ but not plants. I find this remarkable given the importance of plants to all of our lives – from food, medicines, clothing, building materials and biofuels, to climate regulation.” The aim of the report therefore is to provide an assessment of our current knowledge on the diversity of plants on earth, the global threats these plants currently face, and the policies dealing with them. According to the more than 80 scientists involved in the report, there are now an estimated 391,000 plants known to science of which 369,000 are flowering plants. At least 31,000 plant species are used by people as medicines, food, material, animal feed or for other purposes. Among the plant species discovered in 2015 are a massive leguminous tree (Gilbertiodendron maximum), 13 new species from the onion family and 18 species of Ipomoea from Bolivia, among which is a close relative of the sweet potato. “Some areas of the planet exhibit an incredible quantity and diversity of plants, with many unique species. But many of these areas are degrading or disappearing entirely under the assault of increasing threats, including land-use change, climate change, pests and diseases,” the authors warn. According to the report, the biggest threat for plant species is the destruction of habitats for farming (31%), with the expansion and intensification of crop farming as well as livestock farming. The growing international trade in palm oil during the past 20 years, for example, has had significant effects on the conversion of natural forest and peatlands to palm oil plantations. Biological resource use, such as deforestation for timber or the gathering of terrestrial plants are also a major threat (21%), followed by the construction of buildings and infrastructure (13%). There are many emerging threats also occurring with plant diseases caused by fungal, bacterial and viral pathogens. Climate change is still a smaller factor at 4% but is likely to grow over the next decades. “Plants are absolutely fundamental to humankind,” Prof Kathy Willis told The Guardian. “Without plants we would not be here. We are facing some devastating realities if we do not take stock and re-examine our priorities and efforts.” (ab)