XVI International Botanical Congess

Difference in the species concept between Western European and Eastern European (ARussian@) taxonomic schools is well known. A number of species recognized by taxonomists in the East are treated as subspecies, varieties or even synonyms by their Western colleagues. This situation is usually explained by different taxonomic approaches and by the lack of necessary herbarium materials and field observations. However, this is true only in some extent. My study of Euphorbia taxonomy for the whole Europe (started from its east part) has shown that several taxa (especially steppe ones) which can be easily separated in the Eastern Europe do form hardly distinguished complexes (very likely of hybrid origin) in Western Europe. Also some species with local distribution in Western Europe occurring on steppe-like habitats often are not accepted by modern Western botanists. The reason is mainly in extinction of corresponding habitats which are very vulnerable to the men influence and, hence, the lack of the modern material.