Abstract: The subsection Neriiflora Sleumer is one of the largest subsections of Rhododen- dron subgenus Hymenanthes, containing 27 species, 8 subspecies and 24 varieties. All the species are divided into four groups according to morphological characters, relationships am- ong the species and their geographical distribution. The evolution and relationships of the group are discussed. The Group D is of highly specialized morphological characters. The subsection has its modern distribution center in the Hengduan Mountains in south-westernChina.