Eleven characters that characterize potential invasiveness of species or their populations are suggested as the criteria to assess the risk of alien species phytoinvasion. This study is based both on the analysis of the invasive plants’ features in Ukraine and a number of literature sources.

Taxonomical, biomorphological, ecological, coenotical and geographical structure of the flora of plant communities with paleoendemic Chamaecytisus graniticus Rothm. (Fabaceae Lindl.) are studied with its autphytosozological analysis.

Syntaxonomy of hornbeam forests on the boundary between forest-steppe and steppe zones of Right-Bank Ukraine is presented. The communities belong to the class Querco-Fagetea, to the order Fagetalia sylvaticae, to the union Carpinion betuli and 2 associations, four sub-associations and two variants that are new and described for the first time. A comparative and cluster analysis together with phytoindication are applied for justifying description of new syntaxa. The analysis of results shows a sufficient difference between the hornbeam forests on southern edge of its natural distribution and typical hornbeam forests of forest-steppe zone.

The structure of the leaf epidermis surface of 22 species from section Medium DC.of genus Campanula L. in the flora of Ukraine is investigated for the first time using a scanning electron microscope. The common characters for all species (amphistomous type of leaf blade, evenly spaced, not immersed anisocyte stomata, a well-developed crinkled cuticle; awl- and sickle-shaped, bearded and hoary downiness, the location of wax deposits - crusts and / or laminas; a common type of topography) and specific characters (relief type,  peculiarities of hairness) are identified.

A comparative characteristics of flowering time of 15 cultivars and forms of Zizuphus jujuba grown in Kherson region are given. The numbers of the effective temperatures (> 10 º C) at the beginning and at the end of flowering time are presented.

A comparative species analysis for divisions and classes in bryofloras of phytogeographical regions of Ukrainian Livoberezhyarevealed for Levoberzhne Polissya - 272 species (incl. 3 from Anthocerotophyta, 46 - Marchanthoiphyta and 223 species from Bryophyta), for Levoberzhna Forest-steppe - 229 species (incl. 2 - Anthocerotophyta, 28 - Marchanthoiphyta, 199 - Bryophyta), from Levoberzhna Steppe - 290 (1 - Anthocerotophyta, 31 - Marchanthoiphyta, 258 - Bryophyta). Among 385 species of bryobionta in Ukrainian Levoberzhya, 165 species are common for all three phytogeographical areas, that includes less than a half of the bryoflora species (42.8%). Among them, 1 species from Anthocerotophyta, 17 - Marchanthoiphyta and 147 -Bryophyta. Among Bryophyta, Briopsida dominates - 125 species (upper-sporiferous mosses - 71 species, side-sporiferous mosses  - only 54), 13 species of  Sphagnopsida and 9 -  Polytrichopsida. There are 165 species of bryobionta in all three areas of Ukrainian Livoberezhya, 82 species are found in certain two areas; 138 of 385 species of bryobionta are specific for phytogeographical areas that comprizes 35.8% of the bryoflora of Ukrainian Livoberezhya. Among them, 81 species are found in Levoberezhna Steppe, 42 -  Levoberezhne Polissya, and only 15 species - in Levoberezhna Forest-steppe. The Bryoflora Specificity Coefficient (BSC) is offered. Among three Bryofloras studied, the highest meanings of the coefficient are in Levoberezhna Steppe - 21.03, Levoberezhne Polissya - 10.9, the lowest BSC is in Levoberezhna Forest-steppe - only 3.89.

The main morphometric parameters are identified for the 12 species of Chlamydomonas, which belong to the molecular Moewusinia clade, with 15 strains (including 12 authentic) as an example. Those parameters are assessed for the first time on the ground of slant culture as the criteria of the specific and intraspecific level within investigated clade. It is revealed that according to the criteria of the width of the cells within Moewusinia clade, selected strains can be divided into four groups which coincide with molecular - phylogenetic clusters with high bootstrap support. Within each of the group the average length of the cell is the distinguished feature of the specific level. The size of the cell is the base for identification of Moewusinia clade strains in the slant culture.

The characteristics of bryocoenoses with Plagiomniaceae is given with showing the phytocoenotic role of this family. Phytocoenotic tables of the association Plagiomnio cuspidati-Homalietum trichomanoidis (Pec. 1965) Marst. 1993 and outrank community of Plagiomnium cuspidatum – comm. are given.

A floristic structure of the forest, shrub and meadow communities of the Carpathian part of Dnister River is investigated. A list of rare and endangered (red-listed) plant species is added with showing their distribution.

An autosozological analysis of rarities of phytogenetic fund of the national nature park "Beloozerskiy" (10 species) is given together with sinphytosozological analysis of rarities of phytocoenotic fund (18 associations).

In the article, the discovery of Drosera rotundifolia on the lower Dniper sands in Kherson region (Ukraine) is described with a short description of the species’ southernmost locality in Ukraine.