XVI International Botanical Congess

In the Western Regions of Ukraina (7 districts - 110,7 thousand sg. km) 53 Orchidaceae Juss. species of the 24 genera were found. 3098 habitats of orchids found during the last 200 years their quantity were observed. We have mapped natural habitats of orchids used net of squares UTM 10 x 10 km and points marke which were different for data before and after 1950. Depending on quantity of known habitats orchids species are divided on five groups: I - to 10 localities (before 1950 - 12 species, after 1950 - 23 species), extinct: Anacamptis pyramidalis, Dactylorhiza hebridensis, D. ochroleuca, II- 11-50 (22, 19), III - 51-100 (10, 9), IV - 101-500 (2, 2), V - more than 500 localities (0, 0). According to tendency of changing in numbers of localities the species of Orchidaceae are divided on three groups. In Lviv from 35 species 22 disappeared. Sociological evaluation and analysis of the state and optimization of the orchids protection were made. The genus which need special taxonomic investigations are: Dactylorhiza, Gymnadenia, Epipactis, Orchis.