The morphological characteristics have been scrutinized in accordance with local flora (Cheng and Huang 1999, Mu 2012, Meng 2010). Herbarium specimens from PE, IBK, and GXMI herbarium were also carefully examined.
We included DNA sequences of 48 species of Euonymus . All sequences were downloaded from GenBank, except E. duanensis which was generated for this study. Vouchers and GenBank accession numbers are listed in Table S1. Three regions were used for DNA sequencing: psbA-trnH,rp136-infA-rps8, and trnC-ycf6. The protocol of total DNA extracting, Sequences alignment, and phylogenetic tree reconstruction are followed by previous studies (Yu et al. 2016, Qin et al. 2023, Xue et al. 2024, Yang et al. 2023).