|其他摘要||The floristic composition, characteristics, endemism, origin and evolution were studied on the base of literature checked, field investigation, specimens checked and previous research work. The main results are as follows.
1. The Nanxi River Region is rich in seed-plant species. So far, 176 families, 787 genera and 1786 species (including varieties and subspecies) have been recorded from this area. Among them, 5 families, 6 genera and 9 species are gymnosperms; 149 families, 619 genera and 1437 species are dicotyledon, 22 families, 162 genera and 340 species are monocotyledon. During our investigations (2003-2007), 5 new species were found. What’s more, 3 genera are new records in China, 13 species are new records in China, and 8 species are new records in Yunnan Province.
2. The statistic of floristic composition shows that 103 families are tropical which contribute to 58.52% of total families; 33 families are temperate which contribute to 18.75% of tatal families. On the level of genus, 581 genera are tropical which contribute to 73.83% of total genera; 157 genera are temperate which contribute to 19.95% of total genera. And on the level of species, 1044 species are tropical which contribute to 58.62% of total species, 705 species are temperate which contribute to 39.58% of total species. The statistic reveals the fact that Nanxi River Region situates in the border of tropical Asia’s northern parts, its flora has the transitional character of tropical to subtropical, so the Nanxi River Region is an important part when studying the flora of Indo–Chinese Peninsula. On the other hand, this area situates in the crossing place of Holarctic Kingdom and Paleotropic Kingdom, which makes it a key part of tropical flora study.
3. The endemic plants in the limestone flora in Nanxi River Region are rich, 9 genera are endemic to China, 616 species are endemic to China. And among the Chinese endemic species, 49 species are endemic to Nanxi River Region. Among the 9 genera, 8 are primary, which reveals the old character of this flora. And the 46 Region endemic species reflects the fact that the endemic elements differentiated strongly in Nanxi River Region.
4. Besides the tropical character, the rich limestone flora is another character of Nanxi River Region. As far as 9 species of gymnosperms are concerned, 2/3 species are limestone exculusive species. And in the 47 Nanxi River Regional endemic species, 79.59% are limestone exculusive species. While as far as the dominant species in limestone monsoon rain forest are concerned, Excentrodendron hsiemmu, Woonyoungia septentrionalis are also limestone exculusive species. These all reveal the lomestone flora character of Nanxi River Region.
5. After the comparison with four adjacent limestone flora on the level of family and genus, we found the flora of Nanxi River Region is most closely related to the flora of Cuc Phuong (Vietnam). And the analyse on the level of genus and species reveal the fact that Nanxi River Region has a close relationship with Vietnam. So the floristic position of Nanxi River Region is: Paleotropic Kingdom — Malaysian Subkingdom — Tongking Gulf Region.
6. The flora of Nanxi River Region is on the base of tropical-origination and regional-differention, it was affected deeply by tropical SE Asian flora and E Asian flora, which makes it a transitional meeting area of South and North flora.|