Ligusticopsis muliensis, a new combination separated from Peucedanum sensu lato (Apiaceae)

Comparative plastome analyses and phylogenetic reconstruction were used to investigate the phylogenetic position of species and genera within the Apiaceae subfam. Apioideae, which has given rise to many taxonomic revisions concerning the genus Ligusticopsis Leute. Some species from Peucedanum s.l. have been transferred into the genus Ligusticopsis, such as Peucedanum franchetii, Peucedanum nanum, and Peucedanum pubescens. 

During field surveys, Peucedanum muliense was found to be similar to Ligusticopsis scapiformis, but the shape of the apex of the leaflet of the former is more acute and short, the high morphological similarity of Peucedanum muliense to the genus Ligusticopsis indicates that its systematic status requires further investigation. 

In our work, comparative analyses showed that the plastome features of Peucedanum muliense were highly similar to those of nine species from the genus Ligusticopsis but differed from Peucedanum morisonii (represents the Peucedanum s.s.) in terms of the location of genes at the IRa/LSC boundary, codon usage bias in terminator T/A. Phylogenetic reconstructions indicated that Peucedanum muliense does not cluster with Peucedanum s.s., but is nested with species of the genus Ligusticopsis, and that the four accessions of Peucedanum muliense formed a separate branch in the nrITS phylogenetic tree. So it is justified that Peucedanum muliense should be transferred to the Ligusticopsis and is now proposed as a new combination from Sichuan, southwest China.

Here are the nuclear ribosomal DNA internal transcribed spacer (nrITS) and the plastome (plastid genome) sequences of Ligusticopsis muliensis used in the manuscript. These data enrich the DNA information of the genus Ligusticopsis and provide a reference for future taxonomic studies about the genus Ligusticopsis.