New Guinea has greatest plant diversity of any island in the world, study reveals

The tropical island edges out Madagascar as botanists estimate that 4,000 new species could be discovered in the next 50 years

New Guinea is home to more than 13,500 species of plant, two-thirds of which are endemic, according to a new study that suggests it has the greatest plant diversity of any island in the world - 19% more than Madagascar, which previously held the record.

Ninety-nine botanists from 56 institutions in 19 countries trawled through samples, the earliest of which were collected by European travellers in the 1700s. Large swathes of the island remain unexplored and some historical collections have yet to be looked at. Researchers estimate that 4,000 more plant species could be found in the next 50 years, with discoveries showing no sign of levelling off", according to the paper published in Nature.