There are 62 vascular plant genera, including 5 orchid genera, that are found nowhere else but on Borneo. Comprising 162 known species, these unique plants are a small but distinctive subset of the island's still incompletely-known endemic flora. The endemic plant genera of Borneo are presented in this account, with photographs and maps of the known and potential distributions of their species. With the exceptionally high plant diversity of Borneo threatened by rapid land-use change, assessing threats to species uniquely found there, and identifying areas where a significant proportion are harboured, are urgent tasks. Centres of endemism are identified especially in northwest Borneo and are considered against remaining forest cover and protected areas to examine plant conservation exigencies for Borneo. The findings of this study reaffirm the critical need for conservation action to safeguard Borneo's lowland forests and some of its most special species.