Based on the results of own floristic studies, elaboration of herbarium collections from herbarium KW, KRW, CWU, YALT and according to the literary data, the chorology of a rare endemic species Koeleria moldavica in Ukraine and the Republic of Moldova is presented. The species is more widespread than previously thought. In general, K. moldavica habitat covers the steppe regions of the Black Sea Lowland and forest-steppe regions of the southern part of Podilia upland. The ecological characteristic of the habitat of the species is given. Koeleria moldavicа is exclusively limited to limestone outcrops of mainly the middle reaches of the Dniester, Ingul, Ingulets and lower Dnieper regions, where it grows on primitive and poor sod-steppe soils. There are five locations of the species in the lower part of the Dnieper valley, six localities in the Ingulets valley and Vysun river, five localities in the Ingul valley and four in Odessa region. In Republic of Moldova, twelve localities were known mostly in the middle part of the Dniester as vicinity of Rybnitsa and the Yagorlyk River basin. Koeleria moldavica does not form its own formation, rarely it is a subdominant, and often as an assectator. The species is also an important component of many associations of rare formations as Jurineeta brachycephalae, Stipeta capillatae, S. lessingianae, S. asperellae, S. ucrainicae, Botriochloeta ischaemi, Chamaecytiseta granitici, Elytrigieta stipifoliae or Galatelleta villosae. The main anthropogenic and natural factors that lead to the reduction of Koeleria moldavica populations of the species are indicated. To preserve K. moldavicа populations, it is proposed to create new nature conservation reserves in the Odesa, Mykolaiv and Kherson regions and to include the species in the Red Data Book of Ukraine.

Data about the syntaxonomy of plant communities with significant presence of two locally rare in Ukraine halophilous species Frankenia pulverulenta L. and Camphorosma annua Pall. are presented. Communities with Frankenia pulverulenta in Ukraine were discovered by authors for the first time in Northern Black Sea Region (Skadovsk district of Kherson oblast) and in Kerch Azov Sea Region (Lenine district of the Crimea). Based on the cluster analysis of these communities in Juice software using Modified TWINSPAN algorithm these relevés were identified as new syntaxon Puccinelio fominii-Frankenietum pulverulentae Davydova & Davydov ass. nova. The latter belongs to the new for Ukraine high rank syntaxa – the alliance Frankenion pulverulentae Rivas-Martínez ex Castroviejo & Porta 1976, the order Frankenietalia pulverulentae Rivas-Martínez ex Castroviejo & Porta 1976 and the class Saginetea maritimae Westhoff & al. 1962. All these syntaxa of ephemeric halo-subnitrophilous vegetation on saline badlands were known from Atlantic and Western Meditterranean only. Frankenia pulverulenta was previously treatened in Ukraine as attendant species in communities of other halophilous vegetation classes (Therosalicornietea Tüxen in Tüxen & Oberdorfer 1958, Kalideteafoliati Mirkin & al. ex Rukhlenko 2012 and Festuco-Puccinellietea Soó ex Vicherek 1973). Results of the comparative analysis of the vegetation dominated by Camphorosma annua are available too. These communities formed two clusters which are treated as two different syntaxa based on their features of specific composition and environmental peculiarities. The first syntaxon is known in Ukraine as Camphorosmoannuae-Puccinellietumdistantis Shelyag-Sosonko & Solomakha 1987 but it is quite similar to Camphorosmetumannuae Soó 1934 distributed in Central Europe. The latter name has priority by the date of publication so it is to be used for Ukrainian communities. The second syntaxon was described as new association Puccinellio giganteae-Camphorosmetum annuae Davydov ass. nova. Both associations with Camphorosma annua belongs to the order Puccinellietalia Soó 1947 from the class Festuco-Puccinellietea but two different alliances: Puccinellionlimosae Soó 1934 (Camphorosmetumannuae) and Puccinelliongiganteae Golub & Solomakha ex Dubyna & Neuhäuslová 2000 (Puccinellio giganteae-Camphorosmetum annuae). Nomenclatural citations, types and diagnostic species have been presented for all syntaxa.

Data about floristic records ofRudbeckia triloba L. (Asteraceae),a new alien species in Ukrainian flora were reported.The main centers of species introduction in Ukraine are Donetsk Botanical Garden of NAS of Ukraine (cultivated since 1982), M.M. Hryshko National Botanical Garden of NAS of Ukraine (since 1983), Botanical Garden of I.I. Mechnikov Odesa National University and also numerous private gardens (е.g. Uzhhorod, Transcarpathia Region since 1973, Kryvyi Rig of Dnipropetrovsk Region 2013, and Zhytomyr Region 2016). As escaped plants they were recorded in several localitets: Kharkiv (2010),vicinity of village Dachne of Bakhchysaray District, and Simferopol’ (2012), village Zarichne of Simferopol’ District, AR Crimea (2018), Lozova, Kharkiv Region (2014), Chernivtsi (2014), Odesa (2014), Cherniakhiv (2015), Malyn (2017), village Ivnytsia of Andrushivskyi District, Zhytomyr Region (2019), Rachiv (2016), between Perechyn and village Malyi Bereznyi of Velykyi Bereznyi District, Transcarpathia Region (2018). Taxonomical and morphological characteristics, chorological data, ecological and coenotic peculiarities were given.The species has North American origin. It is ergasiophigophyte or colonophyte according to degree of naturalization. Mainly, plants grew in unformed plant communities. In Zhytomyr Polissia, the species was fixed in the composition of union Arrhenatherion elatioris Luquet 1926 (ordo Arrhenatheretalia elatioris Tx. 1931, class Molinio-Arrhenatheretea Tx. 1937) in xero-mesophytic conditions under the full light and union Aegopodion podagrariae Tx. 1967 (ordo Circaeo lutetianae-Stachyetalia sylvaticae Passarge 1967, class Epilobietea angustifolii Tx. et Preising ex von Rochow 1951) in mesophytic conditions under significant shading. The map of distribution of the species in Ukraine was presented.

Ecological as well as ecological and coenotical structure of flora of the «Hadyatskyi» Regional Landscape Park is specified. In relation to the leading environmental factors that are light and moisture, mesophytes (378 species; 39.9%) and heliophytes (449 species; 47.5%) are dominant in the flora of the park respectively. Geographically, mesophytes are representatives of immoral and partly boreal elements. The prevalence of heliophytes among heliomorphs indicates the prevalence of open biotopes in the park. In terms of ecological and coenotic amplitude, hemostenotopes (321 species; 33.9%) and stenotopes (299; 31.6%) occupy the dominant position. This is due to the territory being included into the ecotone section of two natural zones, resulting in many species growing at the border of their habitats and having narrow synecological amplitudes. According to species presence in typical plant groups, asectors (749; 79.1%) are absolutely dominant. Based on the coenotic specimens of the flora, the «Hadiatskyi» regional landscape park is divided into 18 ecological and coenotical groups (steppe, meadow-steppe, sandy-humid, meadow, immoral-forest, boreal-forest, forest, bog non-saline meadow-meadow, saline meadow-meadow, marsh, coastal-aquatic, aquatic, group of species with wide ecological amplitude, ruderal, vegetal and species of other groups).We point out significant participation of species in the groups belonging to zonal vegetation types for forest-steppe - immoral-forest and meadow-steppe (96 species; 10.1%). The presence of anthropogenically transformed areas within the park and adjacent territories affected floristic composition of natural groups. Ecological and coenotical analyzes of the flora show its heterogeneous character. Selected ecomorphsare quite differentiated and indicate a diverse range of ecological conditions of biotopes.

As a result of a study of the mycobiota of the Dnistrovskyi Canyon National Nature Park (Ternopil Region, Ukraine), 337 species of fungi-like protists and fungi were found: 25 species belong to slime molds, 2 – to Zygomycota, 192 – Ascomycota and 118 – Basidiomycota. Four species Neocucurbitaria prunicola, Neomedicopsis prunicola, Polyscytalum neofecundissimum, and Roussoella euonymi, recently have been described by one of the authors as new to science. 21 species Acremonium domschii, Arachnocrea stipata, Bertiella rhodospila, Ceratostomella pyrenaica, Colletotrichum eryngiicola, Cosmospora arxii, Dialonectria diatrypicola, Fenestella media, Hypomyces subiculosus, Isaria fumosorosea , Massaria campestris, Nectriopsis oropensoides, Parafenestella rosacearum, Pseudocosmospora eutypae, P. eutypellae, P. hypoxylicola, Repetophragma inflatum, Stylonectria carpini, Thyronectria rhodochlora, Tolypocladium microsporum and Tympanosporium parasiticum, are new to Ukraine. Another 17 are rare species. Among them: Kavinia himantia, Mucronella calva and Xylobolus frustulatus are indicators of natural, well-preserved forests. Among collected fungi the vast majority are xylotrophic (181 species) and fungicolous (69 species). Other ecological groups remain poorly examined.