The Flora of Samoa project was spearheaded by Hawaii-based ethnobotanist W. Arthur Whistler who worked closely with Samoan partners to explore, collect, and study the Samoan flora, allowing him to incorporate a considerable number of taxonomic treatments emphasizing Samoa’s traditional ethnobotanical knowledge. Whistler dedicated his career to documenting the Samoan flora. After Whistler’s death in 2020, botanists at NTBG and the Smithsonian Institution worked together to complete final editing and updating of the manuscript to ensure the flora was published. Based on Whistler’s 4,900 specimen herbarium collections, the flora is the most current and complete scientific assessment of the Samoan archipelago’s 543 native plant taxa, including 177 endemic species, 290 naturalized flowering plant species, and 225 ferns and fern allies. More than one-third of Samoa’s native plants are found nowhere else on earth. Samoa’s largest family of flowering plants is the orchid family (Orchidaceae), with 101 native species, followed second by the coffee family (Rubiaceae), with 47 native and six naturalized species.