Plants of Palau

Project Managers: Ann Kitalong, Sholeh Hanser, and Michael B. Thomas
The Pacific is the largest biodiversity hotspot region on earth and is arguably the most vulnerable to extinctions. Islands have historically been exceptionally vulnerable to extinctions. In 2004 the IUCN determined that out of all known recorded extinctions from mammals, birds, amphibians, reptiles, and molluscs; 72% were island species.

Although the abundance of endemic and rare plants with restricted distributions in the Pacific is widely acknowledged, little is known about them. Palau, at the western most edge of this region has approximately 130-135 endemic plant species confined to only 453 km². Previous estimates of plant endemism rates for this region have proven to be overestimated by far (Costion & Lorence 2012). Many of these plants are rare, restricted in distribution, and/or very poorly known. Approximately 15% of these are only known from the type collections. A preliminary IUCN red-list assessment of all endemic plant species for Palau (Costion et al. 2009) found that for over 60% of them data was insufficient for establishing a red-list category.

Progress towards a complete IUCN Red Listing of endemic plants in this region is imperative, as threats to the island from development and invasive species are increasing. The lack of a complete understanding of which plant taxa are threatened, and to what degree, remains a significant barrier to effective biodiversity conservation in Micronesia’s most diverse flora. This challenge was addressed in this CEPF project by targeting specific taxa for further collection and population inventory while progressing knowledge on the threatened status
CEPF. 2013. Threatened Plants of Palau. -
Research Checklists
The Golden Key Symbol symbol opens the species list as an interactive key.

Development of the Consortium of Pacific Herbaria and several of the specimen databases have been supported by National Science Foundation Grants (BRC 1057303, ADBC 1304924 and ADBC1115116). Data Usage Policy. Copyright © 2015 University of Hawai‘i.

How to Cite: M.B. Thomas, J.F. Rock Herbarium, University of Hawaii at Manoa. 2015. Consortium of Pacific Herbaria Database (CPH). Available from: (date accessed)

Macroalgal Herbarium Portal | Mycology Collections Portal | North American Lichen Herbaria | iDigBio