The article is dedicated to the study of the formation of phytonymous borrowings of Polish origin. The topicality of the chosen subject is determined by the need to deepen and systematize the data of etymological research of Ukrainian phytonymous borrowings of Polish origin. The aim of the study is to establish ways of archaic groups’ forming of the vocabulary of the modern Ukrainian language of the Western-Slavic origin. The following tasks depended of the aim. – to establish the ways of borrowing of Phytonymous Nomenclature in the Ukrainian language; – to identify the diachronic models of semantic changes in the Proto-Indo-European stems (roots), to which modern Ukrainian plant names are concerned. The botanic borrowings of Polish origin are analized. The research proves that semantic modifications, as in other groups of East-Slavonic botanical names, occur under certain dynamic motivational models (form → name by form, plant → plant, action → subject of action → name by subject, action → object of action → name of object, animal (bird) → name in form, form → habitat → name by place, place → name by place, plant → part of plant → name by part, etc.), and it is accompanied by a number of specific semantic modifications primarily inherent to individual lexical-semantic groups of botanical vocabulary. So, the necessity for the further study of botanical borrowings, is that the motivational foundations, called derivatives, lead to more profound semantic analysis of this lexical-semantic group of words, and also contribute to the further study of etymological character. The requirements of comparative-historical, etymological study of the Slavonic vocabulary arise the task of developing of a more precise lexical and terminological approach to interlingual synonymy phenomena, lexical and semantic parallels, models of nomination (motivational models), search for other permanent inter-system semantic relations. Etymological dictionaries and special lexicological studies of Slavonic languages create a sufficiently enough base for it and contain valuable personal observations that require systematization and theoretical substantiation.