Abstract
The aim of this research is to compile a database of vascular plants found in the Kingdom of Tonga in western Polynesia, a phyto‐geographic subregion of the South Pacific. The Tongan islands are spread over ~600,000 km 2 of the Pacific Ocean between 15–23° S latitude and 173–177° W longitude. The archipelago is comprised of 171 islands with an aggregate land area of about 720 km 2 . Since there is no comprehensive or updated flora for Tonga, we use 143 published sources to compile a database for 1,020 plant species, of which more than 450 are indigenous to these islands. Tonga is noteworthy for its low proportion of endemics, accounting for