关键词: 贡嘎山地区, 杜鹃属植物

Abstract: The Gongga Mountain Region is located on the eastern fringe of Qinghai-Xizang Plateau and the north-eastern end of Hengduan Mountains. As we know so far the genus Rhododendron in Gongga Mountain Region comprise 2 subgenera and 79 species (including 4 varieties and 2 subspecies) The vertical distribution of the genus Rhododendron in Gongga Mountain Region: Eastern slope: There are 16 species of genus Rhododendron at 1090~2200(2500) m alt. in the subtropical evergreen broadleaf forest zone. At the altitude 2500~3600(~3800) m, in the subalpine coniferous forest zone, found 23 species with 1 variety and 1 subspecies, There are 4 species (including 1 variety and 1 subspecies) at the alpine bush and meadow zone. Western slope: There are 16 species with 1 subspecy at 2300~2800(~3000) m alt., in the river valley shrub zone, at the altitude of 3000~4000m, in the subalpine coniferous forest zone, found 42 species with 2 varieties and 1 subspecies. There are 13 species with 1 subspecies and 1 variety at 4000~4600m alt., in the alpine bush andmeadow zone. The floristic composition of the genus Rhododendron in Gongga Mountain Region. 1. One specy is the elements of the Sino-Japanese Subregion. 2. 78 species (including 4 varieties and 2 subspecies) are the Sino-Himalayan Subregion. (1) One species is distributed to Burna;(2) 44 species (including 4 varieties and 1 subspecies belong to endemic distribution of Sichuan; (3) 5 species are endemic species of Gongga Mountain Region. The floristic characteristics of the genus Rhododendron in Gongga Mountain Region are shown as follows: (1) The Gongga Mountain Region is one of the genus Rhododendron distribution centers. (2) The Gongga Mountain Region is one of the genus Rhododendron differentiation centers. (3) The genus Rhoodendron in Gongga Mountain Region have vertical replacement phenomenon.

Key words: Gongga Mountain Region, Genus Rhododendron