 Although most of Australia is semi-arid or desert, it includes a diverse range of habitats from alpine heaths to tropical rainforests, and is recognised as a megadiverse country. Fungi typify that diversity; an estimated 250,000 species — of which only 5 % have been described — occur in Australia. Because of the continent's great age, extremely variable weather patterns, and long-term geographic isolation, much of Australia's biota is unique. About 85 % of flowering plants, 84 % of mammals, more than 45 % of birds, and 89 % of in-shore, temperate-zone fish are endemic. Australia has the greatest number of reptiles of any country, with 755 species.
