Molecular phylogenetics of Asian‐Australian <i>Eriocaulon</i> (Eriocaulaceae) based on one nuclear and three plastid markers

Abstract Eriocaulon is a diverse genus with over 400 species worldwide. It exhibits its highest diversity in tropical regions and Australia accounts for 34 species. Eriocaulon species are found predominantly in the northern region of Australia, with a few extending to central Australia's arid and semiarid artesian springs and temperate areas. This study aims to elucidate species relationships and address species complexes, specifically the E. cinereum complex and the complex associated with E. nanum , E. athertonense , and E. scariosum . To achieve this, we expand on a previous phylogenetic study of Eriocaulon that focused mostly on African and Asian species using one nuclear and three chloroplast DNA regions, adding multiple accessions of all recognized Australian species and species from other continents. Our analysis identified seven major clades, with none found to be endemic to Australia. Our data were not able to fully resolve the E. cinereum complex, which is primarily composed of nonmonophyletic groupings of E. cinereum accessions and exhibits a substantial polytomy but also includes E. australasicum , E. rivicola , and E. scullionii . Our study also found that E. carsonii is not directly related to E. giganticum and E. aloefolium , despite their sympatry and similarities in an isolated semi‐arid spring wetland. Furthermore, all major Australian clades were found to be sister to Asian taxa, suggesting multiple dispersal events between Australia and other landmasses. This study provides evidence for the monophyly of most taxa, highlights the impact of Asian species on the evolutionary history of Eriocaulon in Australia and identifies several previously unknown species.