A new critically endangered tree species depends on unique habitat found only on Kaua`i
(PHYSorg.com Biology)

A new tree species, Melicope stonei (Rutaceae or citrus family), endemic to the Hawaiian island of Kaua`i, is already assessed as Critically Endangered according to IUCN criteria. The newly described Melicope is apparently restricted to unique old growth forest featuring a combination of tree species that are only found on Kaua`i.