Morphological variability of populations of Dactylorhiza maculata (L.) Soó and D. majalis (Reichenb.) P.F. Hunt et Summerhayes (Orchidales, Orchidaceae) from Stara planina mountain (Serbia)

Comparative morphological taxonomic analysis was conducted on two populations of Dactylorhiza maculata (L.) Soó 1962 and one population of D. majalis (Reichenb.) P. F. Hunt et Summerhayes 1965 from the area of Stara planina mountain in order to determine new characters that could be used to distinguish these two species and characters that could eventually be used for defining infraspecific taxa within these species. Taxonomic studies have included processing of quantitative and qualitative characters. A total of 60 characters were analyzed, out of which 34 quantitative and 26 qualitative. Analysis of quantitative and qualitative characters included 90 specimens - 60 of D. maculata and 30 of D. majalis. Based on the results obtained by multivariate statistical analysis and literature data, we selected sets of taxonomic characters that allow a clear differentiation of infraspecific forms within the species D. maculata, which is characterized by intensive variability on the selected localities on Stara planina.