Plastid Phylogenomic Analyses Reveal a Cryptic Species of (Apiaceae, Angiosperms).

is identified and described as a cryptic species from Sichuan Province, China. Although the distribution of this cryptic species overlaps with that of and , the morphological boundaries between them are explicit and have obviously distinguishable characters. The main distinguishing features of the cryptic species are as follows: long conical multi-branched roots, very short pedicels in compound umbels, unequal rays, oblong-globose fruits, 1-2 vittae per furrow and 3-4 vittae on the commissure. The above-mentioned features differ somewhat from other species within the genus , but generally coincide with the morphological boundaries defined for the genus . To determine the taxonomic position of , we sequenced and assembled the plastomes of and compared them with the plastomes of 11 other species of the genus . Notably, both phylogenetic analyses based on ITS sequences and the complete chloroplast genome robustly supported that three accessions of are monophyletic clade and then nested in genus. Moreover, the plastid genomes of 12 species, including the new species, were highly conserved in terms of gene order, gene content, codon bias, IR boundaries and SSR content. Overall, the integration of morphological, comparative genomic and phylogenetic evidence indicates that actually represents a new species.