Abstract:

The genus Rhododendron possesses 58 species,2 subspecies and 8 varieties in Dulongjiang region and these species belong to 6 subgenera. Among them, 1 / 4 are compara-tively more primitive species. There are not many alpine groups and species in this region . which demonstrates that this area is old in geological age and less influenced by the uplift of Qinghai-Xizang Plateau. There are 9 epiphytic species along the river valley which reflects the relic of the tropical ecological enviroment. By the analysis of the endemic species and the distri-bution of other species, this region is regarded as an independent floristic area different to the Hengduan Mountains and Qinghai-Xizang Plateau, but has a close relationship with northeast Burma and its adjacent south-east Xizang. In geological history, they might belong to the same old massif.

Key words: Rhododendron. Floristic composition, Dulongjiang

摘要：

独龙江地区拥有杜鹃花属植物58种，2亚种和8变种，分属于6个亚属，其中较原始的种类占1／4，而较进化的高山类群和种类较少，表明该区地质历史较为古老，而受青藏高原抬升的影响较小，河谷地区出现9个附生种反映了热带生境的残迹。根据该区的特有现象和与邻近地区区系联系的分析，认为在我国的植物区系分区中应是一个独立的小区而有别于横断山脉和青藏高原，并与缅甸东北部和邻接的西藏东南部有着密切的联系，在地史上它们可能同属一个古老的地块。

关键词: 杜鹃花属;区系组成, 独龙江