July 2010 - Taxonomists estimate some 10-20 % of flowering plants remain undescribed, and are threatened

In the July issue of the Proceeedings of the Royal Society B; Biological Sciences, Joppa et al have estimated that 10-20 % of all flowering plants remain undiscovered. Most of them are most probably very rare and local, and disproportionately in biodiversity hotspots, where there
are high levels of habitat destruction.