This paper presents new data on the occurrence of 16 vascular plant species from five Eurasian countries obtained during field explorations, as well as during taxonomic revisions of herbarium materials. Five taxa (<i>Draba fladnizensis</i>, <i>Gentiana orbicularis</i>, <i>Helianthus giganteus</i>, <i>Symphyotrichum cordifolium</i>, <i>Thalictrum alpinum</i>) are recorded for the first time from Poland, five (<i>Achnatherum jacquemontii</i>, <i>Arrhenatherum elatius</i>, <i>Dittrichia graveolens</i>, <i>Geranium pyrenaicum</i>, <i>Stipa</i> × <i>balkanabatica</i>) from Tajikistan, three (<i>Achnatherum sibiricum</i>, <i>Asyneuma thomsonii</i>, <i>Stipa</i> × <i>balkanabatica</i>) from Kyrgyzstan, one (<i>Orobanche bartlingii</i>) from Turkey, one (C<i>alamagrostis obtusata</i>) from China and one (<i>Calamagrostis emodensis</i>) from the Gansu Province in China. In addition, <i>Hieracium piliferum</i>, considered extinct in Poland, was rediscovered. For each species, synonyms, taxonomy with remarks on recognition and differentiation of the species from the most similar taxa occurring in a given area, general distribution, habitat preferences, as well as a list of recorded localities (often far from the previously known areas) are presented. As a result of the morphological comparison of specimens representing <i>Stipa</i> × <i>balkanabatica</i> collected in Tajikistan and Kyrgyzstan with the type specimen collected from Turkmenistan, we decided to describe a new variety named <i>S</i>. × <i>balkanabatica</i> var. <i>alaiensis</i> M. Nobis & Klichowska, <i>var. nov</i>. Additionally, based on the analysis of phytosociological relevés prepared during field studies in the western Pamir Alai Mts (in Kyrgyzstan and Tajikistan), a new association of chasmophytic plants named <i>Asperulo oppositifoliae</i>–<i>Achnatheretum jacquemontii</i> M. Nobis, Klichowska & A. Nowak, is also described.