The results of an integrated research of a potentially invasive species, Asclepias syriaca, in the Romensko-Poltavsky Geobotanical District (Ukraine) are given. The viability of the seeds of this...

We performed a study of the vegetation of afforestation belts in the Middle Dnipro Region of Ukraine. These were planted to protect agricultural land from adverse climatic conditions. The syntaxonomy of these afforestation belts is, so far, embedded in the synanthropic class of Robinietea tree plantations, but over time, these may need another syntaxonomic solution. Based on the data, a phytoindicational assessment of these communities was performed. The ecological features of the vegetation of afforestation belts have been determined by the mutual influence of ecological factors of different origin, and the extent of these impacts. In particular, the climatic conditions and edaphic factors and also the peculiarities of the environment-forming influence of different dominant tree species in the main layers and the age of these plantations, which determines at different stages of sylvestral succession processes. According to our phytoindicational assessment, use of cluster analysis of these biotopes of afforestation belts, proved their considerable similarity taking into account all ecological factors, and the distribution is mainly due to the predominant tree species. As a result of ordination analysis, it was found that the factors that most correlate with the ordinal axes are light regime, soil nitrogen and humidity. Phytocoenoses of afforestation belts are a very specific component of the forest biome in this region, because they have been artificially created.

The leaves of different species of the genus Artemisia show considerable inner and external structural diversity. This paper presents a comparative study of the micromorphological features of leaf surface for seven species from different regions of Ukraine: A. absinthium L., A. annua L., A. dracunculus L., A. marschalliana Spreng., A. vulgaris L., A. argyi H.Lév. & Vaniot, and A. verlotiorum Lamotte. The vegetative organs of these plants have potentially significant value as medicinal raw materials. This study was carried out using both light and scanning electron microscopy. The main diagnostic characteristics for each species – in terms of form and structure of epidermal cells, stomata, and trichomes (glandular and non-glandular) – were described and illustrated. Using combinations of selected qualitative micromorphological characteristics of the investigated species of Artemisia, it is possible to detect the species identity of these raw materials.

The paper presents the distribution of 10 selected invasive plant species in Ukraine. The studied taxa comprised 8 invasive and 2 potentially invasive species. All species were characterized in phytogeographical, biological and ecological terms. Their distribution was shown on grid maps

Amorpha fruticosa L. is a kenophyte of North American origin, ergaziophyte. Currently, this species has naturalized over large areas and has become the background on the coastal waters of the Dnieper reservoirs of hydropower stations. It is necessary to clarify the reasons for the distribution of A. fruticosa populations in different parts of the Middle Dnieper coast under conditions of artificial regulation of its water yield. It has been proven that the high buoyancy of A. fruticosa fruits provides the possibility of its active dispersal along river beds in a natural way under conditions of fluctuations in the level of surface water yield at the time of spring floods. The main and determining factor in the active dissemination of the species on the coast of the Kanev and Kremenchug reservoirs is the frequent variability of the maximum water surface level. The narrow altitudinal span of distribution of this species on the coast in the lower parts and, accordingly, wider span in the upper parts of the reservoirs are determined by the corresponding indicators of water level differences. The possibility of artificial regulation of the water surface level with knowledge of the characteristics of hydrochory of this invasive species makes it possible to influence its distribution in the territory near the reservoirs.

The genus Crataegus L. is one of the largest species in the family Rosaceae Juss. The fruits are used as medicinal raw materials ( Crataegus fructus ), as they contain a set of biologically active compounds. The genus is voluminous and taxonomically problematic due to significant variability, hybridization, apomixis, and polyploidy. As a result, it is difficult to determine the species of the genus. Species of the genus have a number of diagnostic features, one of which is a distinct fruit with seeds. The aim of our study was to identify and compare the diagnostic features of the fruits of seven species of the genus Crataegus flora of Ukraine, which are most often used as medicinal raw materials and are the most common in Ukraine – Crataegus laevigata , C. monogyna , C. pentagyna , C. pseudokyrtostyla , C. sanguinea , C. fallacina , and C. rhipidophylla . The study was performed using scanning and digital microscopy, and descriptions were made by standard methods. As a result, we identified features that clearly distinguished the studied species from each other. We identified mature fruits that contain only one pyrene ( C. monogyna , C. pseudokyrtostyla , C. fallacina , and C. rhipidophylla ), and several pyrenes ( C. laevigata , C. pentagyna , and C. sanguinea ) among the studied species of the genus. The studied species are characterized by spherical and ellipsoidal fruits. The predominant color is fulvous/brown with different shades, but almost-black fruits of the species C. pentagyna are well distinguished. Fruits of all studied species of the genus are fleshy, except C. sanguinea , which is floury. The species is characterized mainly by yellow flesh fruits, except C. pentagyna , which has ribbed fruits. The fruits of C. monogyna plants differ from those of other studied species by the spinous-tuberous surface relief. Pyrenes of triangular shape are observed only in C. pentagyna . We suggest that these features can be used as additional diagnostic tools to determine the species of the genus Crataegus flora in Ukraine.