Biodiversity is essential for well-functioning ecosystems. In each of these 20 countries, over 200 species of plants are threatened, according to data from the International Union for Conservation of Nature available in World Development Indicators.
What's also interesting is that:
Finally, you can have a look at the numbers of threatened species of plants, birds, fish and mammals in the table below. Equador (with the Galapagos Islands) is a huge outlier so makes the bar scale a little awkward below - if you right click on Equador and "exclude" it you'll be able to see the bars on more useful scale.