Neotype for endemic species Centaurea breviceps Iljin (section Pseudophalolepis), which grows in the south of Ukraine, was chosen based on a material from a locus classicus. The sequences and secondary structures of the internal transcribed spacers (ITS) 1 and 2 were annotated. It has been shown that C. breviceps differs from all previously sequenced species of the Acrolophus, Maculosae, Phalolepis and Pseudophalolepis sections by the unique base change in the first helix of ITS2 (C > T, site 41). Within this group of sections, C.breviceps belongs to ribotype "A" represented by diploid and autopolyploid species but not allopolyploids.C. breviceps differs from the three sequenced species of the Pseudophalolepis section (C. pseudoleucolepis, C. protogerberi andC. donetzica) by the secondary structure of ITS1second helix and ITS2 first helix.

The article submitted materials for rare and endangered species of liverworts (Marchantiophyta, Bryobionta) of Ukraine, which are included in the official documents of different levels – in the Red Data Book of European bryophytes (1995), the Red Data Book of Ukraine (2009) Red List of European bryophytes (RLfE, 2014) or proposed for protection and are included in the Red List of bryophytes of Ukraine (Boiko, 2010). 22 species are allocated to rarity liverworts of Ukraine, which are the representatives of 16 genera 13 families of 5 orders of 3 classes – Haplomitriópsida, Marchantiópsida and Jungermanniópsida of Marchantióphyta division. Most representatives of rare species belong to the genus Scapania and family Scapaniaceae. These 22 species proposed for inclusion in the new edition of the Red Data Book of Ukraine.

The paper presents the results of research of Kharkiv bryoflora and the three largest cities of Kharkiv region: Izum, Balakleya and Kupiansk. The list of bryophyte flora is given. It contins information about 104 species and varieties briofitiv and their occurrence in different types of natural and man-made habitats in the studied cities, as well as missing and erroneously of given form. 11 species are newly discovered in Kharkiv region: Bryum dichotomum, B. funckii, B. kunzei, B. subapiculatum, B. violaceum, Grimmia laevigata, Schistidium apocarpum, Didymodon vinealis, Orthotrichum diaphanum, O. striatum and Campylophyllum calcareum. A classic structural analysis of bryoflora urban areas was hold. We gave a rough estimate of the potential bryophyte flora species diversity in undisturbed natural coenoses in modern Kharkiv.

55 species of lichens and lichenicolous fungi on the territory of Kalmiussky department of the Ukrainian steppe reserve (Donetsk region) were found. Among them Rinodina aspersa (Borrer) J.R. Laundon is new species for Ukraine. The largest ecological group is saxicolous (32 species, 71,1 %), fewer presented lichens species growing on the soil (8, 13,5 %). The annotated list of the species are provided. This is the first study of lichens in the department.

The species composition of microscopic benthic algae of the river Southern Bug was studied. There were found 121 species of algae, belonging to Bacillariophyta (86 species), Chlorophyta (20), Cyanoprocaryota(9),Euglenophyta (3), Charophyta (3). In the Southern Bug river there are rare species of the flora of Ukraine: Thalassiosira weissflogii (Grunow)  Fryxell et Hasle,Reimeria sinuata (W. Greg.) Kociolek et Stoermer and Navicula alineae Lange-Bert. was marked as new for Ukraine. There were conducted the ecological and geographical analysis of microscopic algae of the investigated reservoir.

The work is implemented on the analysis basis of rare biodiversity of the region, which is the most vulnerable, is extraordinary fragmented and distinguished by the considerable degradation of ecosystems, capacity of which is mainly exhausted. An analysis of systematic, ecological and geographical structures of sozophytes of Ukraine steppe zone and econet components was realized. It is established that at the territory of projected econet contains 173 species of vascular plants listed in the Red Data Book of Ukraine (RDBU) (2009), i.e. 73,6 % of their number in steppe zone. A comparative analysis of flora of ten leading families of rare species in Ukrainian steppe zone and in the econet components was not found considerable differentiations by its indicators. It is identified that the species of Fabaceae, Poaceae and Orchidaceae families occupy the main places. It is showed that the projected econet mainly represents all conditions to conserve, restore and protect species listed in the RDBU. The found distribution of rare specific composition at territories of administrative regions it could be taken for the reference point to estimate the effectiveness of inclusion of geosystems suitable for their conservation and to develop restoration and protection measures, in particular in the places of the projected econet. Species listed in the RDBU in components of the projected econet of administrative territories occur very unevenly and, of course, is distinguished from the natural. By the likeness Jaccar coefficient between rare flora of the territory of administrative regions and marked in the econet components of steppe Ukraine zone it is defined that Kherson (0,9), Mykolaiv and Donetsk (0,7), Odessa (0,56) regions are the most similar. The rare species of steppe Ukraine zone are insufficiently represented. It is stipulated for the degree of flora and its rare components study. The coefficient of likeness is less in Luhansk, Zaporizhzhya and Dnipropetrovsk (0,5) regions. The least coefficient is typical for Kharkiv (0,4) and Kirovohrad (0,3) regions. This divergence caused by subject reasons requires reconsideration some methodical approaches, in particular in rare part of the Statute on the Econet Formation of Ukraine. First of all, it is related to fixation of the priority principle of representativeness in the econet components of all or maximally full rare phytodiversity of the administrative region or physico-geographical territory. The task of fullness problem of population representativeness of rare species is also very important and should be decided.

This paper presents data concerning the conditions of the population of two species of white pearl cornflowers – Centaurea appendicata Klokov and C. konkaе Klokov (section Pseudophalolepis Klokov) – on the banks of the Kakhovka Water Reservoir. Both species are extremely rare, local endemics of the lower Dnepr sands, included in the Red book of Ukraine. In the article the syntaxonomy of sandy communities with their participation are established, and the nature of the data population is presented. The factors influencing the decline of these species are determined in the article and measures  to protect these species are proposed.

The representation of rare and endangered species of the genus Astragalus L. (Fabaceae)of Ukrainian natural flora in protected territories, collections of botanical garden and dendrological parks was identified and analyzed for partial evaluation of success in implementation of the targets 7 and 8 of the Global Strategy for Plant Conservation in the country until 2020. There aren’t 4 species or 19 % of this group (A. sareptanus A. Beck., A. zingeri Korsh., A. calycinus M. Bieb.) in territories of natural reserved fund of Ukraine. There are 12 species rare and endangered species saved in culture. We allocated 5 species which could be involved in the programs for the restoration and rehabilitation of ecosystems in the short term (A. cicer L., A. cretophilus Klokov.,A. glycyphyllos L., A. odessanus Besser, A. ponticus Pall.). There aren’t 3 rare and endangered species (A. exscapus, A. sareptanus, A. calycinus) provided by ex situ and in situ conservation in Ukraine now.

The results of geographic study by Meusel (Meusel, Jager, Weinert, 1965; Meusel, Jager, 1992) of the synanthropic flora of Biloozersky National Nature park showed that the temperate-submedional species (43,7 %) are prevail in latitudinal spectrum of chorological groups. It is typical for flat temperate latitudinal floras of Holarctic region.

The species of Euroasian group, which have Europe and circumpolar area are distributed in temperate area boreal zones and predominante in spectrum of regional chorological groups of flora.

Cosmopolite species are minor in studied flora. The species of Euryoceanic and indisferent groups are predominante by oceanic-continentality. In general correlation between oceanic and continental climat types of areas confirms intermediate character of flora of park. Thus, the division of areal groups of flora is evidens of its forest-steppes character of Middle European floras.

In context of the econet forming for forest-steppe zone of Ukraine authors justified the segregation of 52 national key territories and 78 regional ones. Their typological analysis has been given. Rare phytocoenofond of national key territories (including 156 associations) and regional ones (including 95 associations) had been determinated. Rare associations had been analyzed by associatiated character of dominated species in communities, authphytosozological value of dominants, botanical-geographical significance,  sozological status. Their sozological categorization has been made; data about distribution of rare syntaxa on segregated key territories of the econet and their protection level have been generalized. The comparative sozological analysis of Right bank of Dnipro area and Left bank of one within forest-steppe zone of Ukraine has been realized.

Non-native floras of 13 protected areas, located within the range between 51˚43′09″ – 48˚23′57″ N and 26˚10′00″ – 37˚47′00″ E have been studied. These floras represent the plant diversity of the Ukrainian Forest Steppe. Preconditions for the establishment of alien floras comprised a number of abiotic and biotic factors of the recipient ecosystem. At the level of a protected area, the preconditions included location in terms of natural zoning, total area, land-use structure, river banks, transport routes, and period of time under protection. At the level of a single flora, the main preconditions were total number of species, share of alien species, and possible threats of invasions from the surrounding areas. A taxonomic list included 364 alien species, 90 (25 %) of which were casuals. The number of alien species in the studied floras ranged from 52 to 229, while the total number of species varied from 418 to 1138. The share of non-natives ranged from 9 to 28 %, with the average of 16 %. However, after casual alien species had been excluded, it was 8 –26 %, with the average of 14 %. The number of non-natives was increasing as the number of indigenous species and the total number species were increasing too. The resident floristic and habitat diversity within the studied areas didn’t seem to be a barrier for penetration and naturalization of alien species. However, a weak inverse correlation between the proportion of non-natives and native species numbers allowed us to assume that the number of native species, corresponding to the "complete flora", served as a penetration barrier for exotic species.

The results of morpho-biological and the main economical signs (productivity, content and chemical composition of essential oils) studies of Thymus roegneri have been given. The sample has been introduced from native flora of the Crimean Mountains (Ay-Petri mountain plateau), vegetatively propagated and planted on the introduction and breeding ground. In the introduction conditions of Nikitsky Botanical Gardens Th. roegneri plants undergo a complete cycle of their development, give mass of flowers and fruits. Th. roegneri is a semishrubs height of 25–30 cm, stems are densely covered with short hairs. Leaves are dark green, oblong-elliptical. Inflorescence is elongated, consists of 2–3 whorls. Corolla is mauve. Mass fraction of essential oils in the period of full blossoming is 0,5–0,6 % of the fresh weight. It has been identified 31 components. Essential oils have 39,1 % geraniol, 28,5 % geranilacetat and 16,9 % thymol and are perspective for use in food producing industry and parfumary.