Two New Species of <i>Primula</i> Sect. <i>Auganthus</i> From Sichuan, China

In groups undergoing rapid radiations, species delimitation among phylogenetically close sister lineages has long been a challenge. During plant surveys in northwestern Sichuan, we unexpectedly discovered two putative new species of <i>Primula</i> that are morphologically similar yet distinct from each other. These species resemble <i>P. xingshanensis</i>, which has been assigned to sect. <i>Auganthus</i> based on morphological characters. To clarify the precise phylogenetic positions of the two putative new species and <i>P. xingshanensis</i>, we sampled related taxa and conducted phylogenetic analyses using chloroplast genomes and nuclear SNPs. The results showed that the two putative new species form sister clades and are closely related to <i>P. sinensis</i>, while <i>P. xingshanensis</i> is sister to <i>P. rupestris</i>. All belong to the sect. <i>Auganthus</i>. Based on population genetic structure, morphological statistics, and artificial hybridization experiments, both putative new species should be accepted as distinct species, herein formally described as <i>P. rongrong</i> sp. nov. and <i>P. fujiangensis</i> sp. nov. Based on our field surveys and in accordance with the IUCN criteria, we assess the conservation status of <i>P. rongrong</i> as least concern (LC) and <i>P. fujiangensis</i> as critically endangered (CR).