Patterns of Morphological Variation in Colchicum s. l. (Colchicaceae, 1804) Species along Climatic Gradients in European Russia

Variability of morphological traits in Colchicum s. l. was studied in European Russia from 2021 to 2024 in four populations of C. ancyrense, 18 populations of C. bulbocodium subsp. versicolor, 12 populations of C. laetum, 14 populations of C. trigynum, and two populations of C. eichleri. Thirty generative-state plants were randomly selected from each population, and 32 morphometric parameters were measured. Nonmetric multidimensional scaling (nMDS) was used to reveal the main patterns of variability. To identify the relationship between the observed pattern of variability and the most biologically significant environmental factors, 19 bioclimatic characteristics from the open WorldClim ver. 2.0 database and altitude (with 30' resolution) were used. It has been shown that the morphological characteristics of plants and the geographic distribution of species are explained primarily by the spatial seasonal distribution of temperature and precipitation, in particular, the total precipitation in the spring months. The observed differences clearly reflect the proposed phylogenetic relationships between species: the most distant from each other are species that were previously classified in different genera (Colchicum, Bulbocodium, and Merendera); as representatives of the genus Colchicum s. str., C. laetum, and C. ancyrense are relatively closely related species; C. trigynum and C. eichleri differ slightly in their variability, confirming their evolutionary relationship and justifying their unification into a single species, C. trigynum.