Abstract <p>The results of the study of plant communities of Mountainous Dagestan with the rare endemic species goat’s-wheat (<i>Atraphaxis daghestanica</i> (Lovelius) Lovelius) are given. The taxonomic structure of communities is considered, geo-elements are analyzed, and endemic species of the Caucasus are identified. We have described 79 plant species assigned to 65 genera and 31 families in communities with <i>A. daghestanica</i>. The analysis of the flora shows the domination of the Caucasian xerophilic element of the boreal group of species, which testifies to the great autochthony of the development of communities with the participation of the rare species <i>A. daghestanica</i> in the arid part of the Eastern Caucasus and to the high proportion of endemics: among 18 species, there are 11 (61%) endemics of the Caucasus, two endemics of the Greater Caucasus, and five endemics of the Eastern Caucasus. The results of the study of these communities are presented for the first time and may be used for monitoring rare endemic species growing in arid conditions of the Eastern Caucasus.</p>