XVI International Botanical Congess

About 25 species of Crataegus L. occur in Europe and 15 species are distributed in Central European conditions. The hawthorns during the last two thousand years in the changing biocenoses under the human activities have been created a specific and important plants communities Crataego-Prunetum or as sole individuals at the Carpathian region. For taxonomical analyses some methods of caryology and chrology have been used at last ten years investigations. About 14 species and some interspecific hybrids were identified. The next species and nothospecies were observed: Crataegus laevigata (Poir. in Lam.) DC., C. palmstruchii Hrabetová-Uhrová, C. macrocarpa Hegetschw., C. monogyna Jacq., C. rosaeformis Janka, C. curvisepala Lindman, C. fallacina Klokov, C. ovalis Kit., C. lindmanii Hrabetová-Uhrová, C. plagiosepala Pojarkova, C. kyrtostyla Fingerh., C. dunensis Cinovskis, C. domicensis Hrabetová-Uhrová, C. x deltoxyacantha (pénes) Baranec, C. x intermixta (Wenzig) Beck, C x uhrovae Soó, C. x roubalii Chrtek et Krísa, C. x silicensis (Hrabetová-Uhrová) Baranec. To the genus Cotoneaster belong 5 species distributed in the territory of West Catpathians: Cotaneaster tomentosus (Aiton) Lindl., C. integerrimus Med., C. nigra (Ehrh.) Fries, C. alaunicus Golitsin, C. matrensis Domokos.