A total of 1124 species of Pteridophyta (including Lycopodiopsida) from 170 genera and 38 families have been identified in the Socialist Republic of Vietnam. Many species are quite widespread not only in natural habitats, but are also present in arable land and in urban plant communities. In ruderal and synanthropic habitats we noted 82 species from 38 genera and 17 families, among which 20 are introduced species, and 62 are native species that can occupy biotopes and cenoses that are not typical for them in nature. Most fernlike plants were observed in the synanthropic and disturbed habitats. The government of Vietnam is actively developing a legislative framework on the issues for combating alien species, yet those domestic standards need to be brought into line with international ones.

S.S. Kalyuzhny