Morphological Variability of Two Closely Related Species of the Genus Orchis in Various Growing Conditions

The structure of morphological variability in individuals of two closely related species (Orchis punctulata Steven ex Lindl. and O. purpurea Huds.), growing in forest and steppe communities, was studied. Over several years of observations (2015–2023), six populations were examined. A total of 12 morphological traits were analyzed in 375 generative individuals of O. punctulata and 356 generative individuals of O. purpurea. The following methods were used for analysis: correlation, principal component analysis, and linear discriminant analysis. It was found that environmental conditions affect most (58%) of the morphological traits of Orchis punctulata, whereas they do not influence the vast majority (83%) of traits in O. purpurea. Ordination using principal component analysis and discriminant analysis also showed a separation of O. punctulata populations from forest and steppe communities, while the populations of O. purpurea from these communities were morphologically homogeneous. The differences in the morphological variability of these two closely related species can be explained by different mechanisms of life strategy formation.