SUMMARY. Galinsoga parviflora and G. quadriradiata are among the most successful invasive species of the family Asteraceae, having actively spread across Europe and other continents since the late 18th century. Despite the sig-nificant impact on agroecosystems, the genetic structure of their populations remains insufficiently studied using molecular approaches. Using sequencing and bio-informatic analysis, we characterized the polymorphism of the chloroplast DNA intergenic spacer rpl32-trnL (UAG) in Galinsoga samples from Ukraine, other European countries, and China. It was found that the vast majority of G. parviflora and G. quadriradiata samples are represented by two main haplotypes, Par1 and Qua1, indicating low genetic diversity of these species within their secondary range and supporting the hypo-thesis of a single introduction involving a limited amount of source material. Four rare haplotypes were also identified, which likely originated within the inva-ded range. It was shown that in hybridization between G. parviflora and G. quadriradiata both species can act as the maternal parent. The effectiveness of the rpl32-trnL(UAG) region for genetic barcoding was confirmed, and it was found that G. parviflora dominate in the central and northern regions of Ukraine, while G. quadriradiata prevails in the western regions of the country.
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