云南樟科植物区系地理

THE FLORISTIC GEOGRAPHY OF LAURACEOUS PLANTS IN YUNNAN

From the study of the geographical distribution of Lauraceous 22 genera and 209 species in Yunnan Province, the distribution-patterns of genera and species are discussed. The distribution-patterns of genera are divided: Pantropic, Tropical Asia, Eastern Asia-North America, Tropical America and Tropical Asia, as well as Endemic in China. From the analysis of the primitive forms in Yunnan Province, the author discussed the origin of related genera. Furthermore, the author also counted up the number of Lauraceous plants for each genus in relation to the floristic regionalization in Yunnan Province. The distribution-patterns of species are divided: Tropical America, Old World Tropic, Tropical Asia, Mediterranean, Eastern Asia and Endemic in China. From the analysis of the distribution-patterns of 209 species in Yunnan Province, it was found that SE Yunnan is of great abandance in endemic species. It may be explained by the fact that this area is of high antiquity and the one of regionsor a part of region where Lauraceous plants were originated. The great similarity of Lauraceous flora distributed in Yunnan, Sichuan, Xizang, Hainan, Guangdong as well as Guangxi is existed. The region south of Yangtze River in China is the area where Lauraceous plants were widely distributed after their speciation because of the stability in its geological history.