Ecological analysis of the existing phytocoenological relevés was carried out, including the new localities of Thesium ebracteatum Hayne in the Middle Dnipro region. To study the coenotic features, the ratio of diagnostic species of different classes of vegetation in the communities was found. In the western part of the area, including the territory of Ukraine, this species grows in psamophytic communities, the basis of which is species of the Trifolio-Geranietea sanguinei class. In the eastern part of the area, including the territory of the Russian Federation, the species grows in steppe communities with a predominance of species of the Festuco-Brometea class. The analysis of ecological features of the species using the method of phytoindication showed the two clusters with the biggest differences by the acidity indicator. In the central part of Ukraine and in Europe, this species grows on soils with a higher acidity. On the contrary, in the eastern part of the area (territory of the Russian Federation), it mostly occurs on carbonate-enriched soils with low acidity. The growth of T. ebracteatum on more acidic soils in the western areas should be explained by a more humid climate.
