Complete plastid genomes have been proposed as potential “super-barcodes” for plant identification and delineation, particularly in cases where standard DNA barcodes may be insufficient. However, few studies have systematically addressed how taxonomic complexity, especially in rapidly radiating lineages with intricate evolutionary histories, might influence the efficacy of plastome-scale barcodes. Pedicularis is a hyperdiverse genus in the Himalaya-Hengduan Mountains, and previous studies have demonstrated high discriminatory power of the standard barcodes within this genus. Therefore, Pedicularis serves as a model for investigating the key plastome-sequence characteristics and biological phenomena that determine species-discrimination capacity. In this study, we evaluated 292 plastomes representing 96 Pedicularis species to compare the discriminatory power of complete plastid genomes with of standard DNA barcodes. Our results revealed that the traditional standard barcode combination (nrITS + matK + rbcL + trnH-psbA) achieved the highest discrimination rates (81.25%), closely followed by the plastid large single copy (LSC) region (80.21%), then by full plastome, the supermatrix of protein-coding genes, and hypervariable regions (79.17%). Notably, the matK and ycf1 gene alone could discriminate 78.13% of species. Key determinants of species discrimination by integrating alignment length (AL) and the proportion of parsimony-informative sites (PPIS), as well as conserved genes under relaxed selection exhibiting stronger discriminatory capacity. Unlike previous studies that demonstrated superior discrimination rates of plastome-scale barcodes, this study reveals a notable exception of minimal differences between traditional DNA and plastome-scale barcodes that appearing linked to Pedicularis’ specific biological habits and potentially reflecting unique evolutionary patterns in the plastid genome.

Over the past century, anthropogenic greenhouse gas emissions have continuously increased global temperature and triggered climate change, significantly impacting species distributions and biodiversity patterns. Understanding how climate-driven shifts in species distributions reshape diversity patterns is crucial for formulating effective future conservation strategies. Based on the distribution data of 314 Rhododendron species in China, along with 16 environmental variables, we examined spatial diversity patterns and assessed regional and biome differences in species responses using ensembled species distribution models. Our results indicated that climatic variables significantly influenced species distributions, with ongoing climate change expected to concentrate Rhododendron distribution patterns and alter species composition. Regional topography played a critical role in shaping species responses to global warming. In the mountainous areas of southwestern China, species exhibited heightened sensitivity to temperature fluctuations, shifting upward as temperature increased. This region also had a higher proportion of threatened species and showed an overall contraction in primary distribution range. Conversely, in southern China, species were more influenced by precipitation, exhibiting a notable northward shift and expansion in primary distribution areas. Notably, alpine species, occurring in habitats above the treeline, may face severe survival risks due to the high degree of habitat loss and fragmentation. We identified seven priority conservation areas, predominantly situated in highly fragmented mountainous regions that were inadequately protected by existing nature reserves. Our findings contribute to a better understanding of changes in Rhododendron diversity patterns under climate change, providing valuable insights for developing comprehensive, flora-wide conservation plans in China.