The flora of St Helena is particularly distinctive, with circa 420 higher plant species present in the wild, of which 45 are endemic and a further 15-20 are native to the island. The rest (350 spp. 85% of the total) are introduced species that have become naturalised. At least 8 endemic species are now thought to be extinct and all of the endemic species on the island are scarce and likely to be Critically Endangered (although formal assessments have not yet been made for all species).