The morphological variability in populations of Chondrilla was subject to the numerical analysis using the unweighted pair group method with arithmetic mean (UPGMA). The study showed that out of the seven species of the genus found in European Russia, it is only C. ambigua that has the status of undoubted species. A distinct difference is observed between the two groups of populations: the first group comprising C. juncea, C. latifolia, C. brevirostris, and the mixed population of C. juncea/graminea; and the second group comprising the populations of C. graminea and C.
