Phylogeny, species delimitation, and biogeographical history of Bredia

Species delimitation in plants are sometimes challenging due to morphological convergence, interspecific gene flow, and historically limited specimens sampling. Bredia as currently defined comprises 27 species and has been resolved as monophyletic in previous phylogenomic studies. However, relationships among several major lineages in the genus remain elusive, and the species boundaries of some problematic taxa have not been tested due to limited sampling. In this study, we reconstructed the phylogeny of Bredia using single-copy orthologs (SCOs), genomic single nucleotide polymorphisms (SNPs), and whole plastomes, employing comprehensive taxon sampling.