A comparative cytogenetic study of two introduced forms of Makleaya cordata (Willd.) R. Br. = syn. Bocconia cordata Willd. grown in different ecological and geographical regions (Moscow and Donetsk areas) was carried out. In the study, a complex of methods utilizing various chromosomal markers, i.e., C- and DAPI-banding technique, fluorescence in situ hybridization (FISH) with probes of 26S and 5S rDNA, as well as estimation of the total area of C-positive regions (C-HCH) in prophase nucleoli and meiosis analysis, was used. In the karyotypes (2n = 20), each chromosome was identified on the basis of C-banding and FISH patterns and the chromosome ideograms were built. Pericentrometric and telomeric C-positive bands in chromosomes of the Moscow form karyotype were found to be smaller and intercalary bands, larger than the corresponding bands in the M. cordata form grown in Donetsk. It was found that the content of C-HCH in prophase nucleoli in the form of M. cordata grown in Donetsk was higher than in the form grown in Moscow. In both forms sites of 26S rDNA and 5s rDNA were localized on satellite chromosome 1 and on chromosome 4 respectively but the signals were more intensive in the plant form grown in Donetsk. The results of this study enable selecting M. cordata forms for use in pharmacology and recommending them for cultivation in various ecological and geographical regions. © 2012 Pleiades Publishing, Ltd.