A generic term for an area high in such biodiversity attributes as species richness or endemism. It may also be used in assessments as a precise term applied to geographic areas defined according to two criteria (Myers et al., 2000): (i) containing at least 1,500 species of the world’s 300,000 vascular plant species as endemics, and (ii) being under threat, in having lost 70 % of its primary vegetation.