Dariganga MunkhulgaP, Shukherdorj Baasanmukh, Hyeok Jae Choi

Department of Biology and Microbiology, Changwon National University, Changwon, South Korea

Oxytropis L., comprising more than 600 species worldwide, is one of the largest and most diverse genera in the Fabaceae. In Mongolia, Oxytropis comprises 100 taxa including 13 endemic and 36 subendemic species which is one of the most species-rich genera of Fabaceae and a key component of steppe, mountain, and desert-steppe floras. Despite long-standing botanical exploration, the taxonomy and distribution of Mongolian Oxytropis remain incompletely resolved due to morphological similarity among closely related taxa, under-sampling in across regions. Here, we integrate field surveys conducted in Mongolia (2017–2025), examination of herbarium material, and complete plastome-based phylogenetic to reassess species boundaries within the genus. As a result, we currently described the four new Oxytropis species from Mongolia based on morphological and molecular evidence: O. oyunmaae Munkht. & Baasanm. (sect. Verticillares); O. jamsranii Munkht. & Baasanm. (sect. Xerobia); O. dariimaae Munkht. & Baasanm. (sect. Verticillares), and O. ikhbogdicus Munkht., Baasanm. & H.J.Choi (sect. Mesogaea). In addition, O. sobolevskajae Pjak, previously described in the Republic of Tuva, Russia, is newly recorded to the Mongolian flora. Our results highlight that Mongolian dryland and montane landscapes still harbor overlooked legume diversity and emphasize the need for continued integrative taxonomic work to support biodiversity inventories and conservation planning.