The identity of Bupleurum jeholense (Apiaceae)

Bupleurum jeholense Nakai (Apioideae, Apiaceae), originally found in the Wuling Mountain of China, was initially described as a species but later treated as a variety of B. sibiricum Vest ex Spreng. However, researchers have recently found that it is more closely related to B. chinense DC. In this study, we conducted morphological and phylogenetic analyses as well as chromosome counting to determine the taxonomic status of B. sibiricum var. jeholense (Nakai) Chu. Our results showed that B. sibiricum var. jeholense and B. chinense share common features (i.e., bracteoles 5 and stem solid) that distinguish both from B. sibiricum var. sibiricum. The chromosome number of B. sibiricum var. jeholense was found to be the same as in B. chinense (i.e., 2n = 12), whereas the chromosome number of B. sibiricum var. sibiricum was 64. A phylogenetic tree based on complete chloroplast genome data revealed a close relationship between B. sibiricum var. jeholense and B. chinense. Finally, B. sibiricum var. jeholense and B. chinense were mainly found to differ in plant height, number of stems, and middle stem leaves. Based on this evidence, we propose a new combination: Bupleurum chinense var. jeholense (Nakai) Q.R.Liu & L.H.Wang.