1. Institute of Dendrology Polish Academy of Sciences, 62-035 Kórnik, Poland
2. Faculty of Biological Sciences, Kazimierz Wielki University, 85-064 Bydgoszcz, Poland
3. Botanical Institute of Spanish Research Council, 08038 Barcelona, Spain
4. Department of Botany, Ivan Franko National University of Lviv, 79005 Lviv, Ukraine
5. M.G. Kholodny Institute of Botany, NAS of Ukraine, 01601 Kyiv, Ukraine