Mattio Lydiane auteur aut IRD Payri Claude auteur aut IRD text journalArticle eng text/pdf born digital access Sargassum C. Agardh (1820) is a taxonomically difficult genus distributed worldwide and reported as the most species-rich genus of the Fucales. It is especially abundant in the Pacific where decreasing species richness is reported to occur from west to east. New Caledonia has been recognized as one of the hotspots of Sargassum diversity; however, species lists available for this region are old and incomplete and have not yet been updated with regard to the latest taxonomic revisions published. This study aimed at revising Sargassum diversity in New Caledonia and to assess its geographic affinities with neighboring Pacific regions. We used combined morphological and DNA analyses on new collections and examined numerous type specimens. Although 45 taxa have been listed in the literature, most of them have been either transferred to synonymy since or misidentified, and in this study, only 12 taxa were recognized as occurring in New Caledonia. They belong to the subgenus Sargassum sect. Binderianae (Grunow) Mattio et Payri (2), sect. Ilicifoliae (J. Agardh) Mattio et Payri (2), sect. Polycystae Mattio et Payri. (1), sect. Sargassum (4), sect. Zygocarpicae (J. Agardh) Setch. (2), and subgenus Phyllotrichia (Aresh.) J. Agardh (1). New Caledonian Sargassum flora appeared as the second richest in the region after the Pacific coast of Australia, with which it has shown high similarity, and shared species with all neighboring regions. One species, S. turbinarioides Grunow, is considered as endemic to New Caledonia. The low genetic diversity detected among several polymorphic species belonging to sect. Sargassum is also discussed. specialized biogeography cox3 DNA phylogeny endemic ITS-2 Phyllotrichia rbcLS Sargassum turbinarioides taxonomy 034 45 6 1374-1388 2009 0022-3646 https://www.documentation.ird.fr/hor/fdi:010049173 10.1111/j.1529-8817.2009.00760.x 0022-3646 [F B010049173] https://www.documentation.ird.fr/hor/fdi:010049173 https://www.documentation.ird.fr/intranet/publi/2010/01/010049173.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2010-02-08 2026-01-15 fdi:010049173 fre