We identified and described Cortiella yatungense, a new species of Cortiella (Apiaceae) from Xizang, China. This species can be distinguished from other members of this genus (C. hookeri, C. caespitosa, C. lamondiana, and C. cortioides) by fewer umbels (3–6), thinner and longer pedicels than the leaves, ovate to suborbicular fruits, and mericarp without vittae. Molecular phylogenetic analyses based on the internal transcribed space (ITS) region and two chloroplast DNA intron sequences (rpl16 and rps16) showed that C. yatungense was sister to C. hookeri with strong support. Thus, both morphological and phylogenetic evidence suggested that C. yatungense is a distinct species of Cortiella. A comprehensive description of C. yatungense along with morphological characteristics and habitat are provided.

In this study, morphological and molecular evidences were combined to determine the taxonomic position of Peucedanum pubescens Hand.-Mazz. Morphologically, Peucedanum pubescens is similar to the species of the genus Ligusticopsis in having fibrous remnant sheaths at the stem base, pinnate and linear coexisted bracts, strongly compressed dorsally mericarps, filiform median and lateral ribs, winged marginal ribs, numerous vittae in each furrow and commissure, but can also be easily distinguished from members of Ligusticopsis by its hispid fruit and linear-lanceolate bracteoles. Molecular phylogenetic analyses based on the single-copy protein-coding sequences (CDS) of plastomes and internal transcribed space (ITS) region showed that Peucedanum pubescens nested in the genus Ligusticopsis. As both morphological and molecular data supported the inclusion of Peucedanum pubescens within Ligusticopsis, the species is here transferred and the new combination, Ligusticopsis pubescens (Hand.-Mazz.) J.J.Deng, C.K.Liu & X.J.He, made.

Peucedanum nanum and P. violaceum are recognized as members of the genus Peucedanum because of their dorsally compressed mericarps with slightly prominent dorsal ribs and narrowly winged lateral ribs. However, these species are not similar to other Peucedanum taxa but resemble Ligusticopsis in overall morphology. To check the taxonomic positions of P. nanum and P. violaceum, we sequenced their complete plastid genome (plastome) sequences and, together with eleven previously published Ligusticopsis plastomes, performed comprehensively comparative analyses. The thirteen plastomes were highly conserved and similar in structure, size, GC content, gene content and order, IR borders, and the patterns of codon bias, RNA editing, and simple sequence repeats (SSRs). Nevertheless, twelve mutation hotspots (matK, ndhC, rps15, rps8, ycf2, ccsA-ndhD, petN-psbM, psbA-trnK, rps2-rpoC2, rps4-trnT, trnH-psbA, and ycf2-trnL) were selected. Moreover, both the phylogenetic analyses based on plastomes and on nuclear ribosomal DNA internal transcribed spacer (ITS) sequences robustly supported that P. nanum and P. violaceum nested in Ligusticopsis, and this was further confirmed by the morphological evidence. Hence, transferring P. nanum and P. violaceum into Ligusticopsis genus is reasonable and convincing, and two new combinations are presented.