XVI International Botanical Congess

Being largest family of flowering plants in Vietnamese flora Orchidaceae reflects representatively florogenetic elements composition of all flora of the country. For a millions years mountain ridges of Vietnam served as migration bridges connected main centers of world biodiversity - Mainland Asia and Malasia. This is a main cause why Vietnamese flora is very diverse and hetergeneous florogenetically. It includes a great number of groups of species having quite different geographical origin. Under careful analysis of the species distribution all orchids are ranged into florogenetic groups having similar migration history. Next main groups of species are revealed - pantropic (0.3%), paleotropic (0.4%), S.Asia-Australic (2.4%), Asian (96.3%). Asian species are divided into - S.Asian (3.6%), E. Hymalayas-SE Asian (6.9), Indochinese-Malasian (10.9%), mainland-S.Asian (72.8). Are also geographically outlined the main centers of Indochinese (10.9%) and Vietnamese (19.2%) endemism that represent most specific autochtonal elements of the flora.