Abstract: The seed surface of 12 species of Impatiens L. from Mt. Omei was observed under SEM for the first time. The important characters used in the paper include cell specialization on seed surface, arrangement pattern of the cells, the degree of the cell elevation, chalazal zone morphology and appendix at the tail of the seed. According to these characters, the seed surface morphology of 12 species can be divided into two types: 1. the seed without conspicuous differentiation of surface cells, laevigate on the surface, represented by I. wilsoni; the seeds of species indicated by 3-colpate pollen grains are expected to belong to the type. 2. the seed with the large cell elevation at different levels, surface scabrous, represented by the other 11 species; most species with 4-colpate pollen have this kind of seeds. The results verify that the seed morphology of the genus can supply characters significant to taxonomy of the genus at species level. The evolution of seed surface of Impatiens has close correlation with that ofthe flower and pollen morphology.

Key words: Impatiens, Seed Surface, Taxonomy