ABSTRACT

The Caribbean Island Biodiversity Hotspot is composed primarily of the Bahamas and Greater and Lesser Antilles. A total of 180 genera (727 spp., ca. 9% of the species endemic to the Antilles) are restricted to this hotspot. Most of these genera are unispecific (51%), a pattern that is also found on other islands of the world. The majority of the endemic genera belong to the “Core Eudicot” clade, and they were published in two time periods (1854–1878 and 1904–1928). There are molecular phylogenies available for 63 of the endemic genera. However, phylogenetic reconstructions of only 21 genera are based on more than one independent DNA region and have well-supported clades and good taxonomic sampling. Six of the endemic genera form part of early-branching groups. We could not infer biogeographical conclusions from the molecular phylogenies of most of the endemic genera (43: 68%). There is an urgent need for (1) additional field studies to learn the conservation status of these genera, (2) effective protection of the habitats where the most endangered genera occur, and (3) additional biological and systematic studies of the least understood genera.