Abstract: In the present study, the pollen morphology of 10 species in Impatiens L. has been examined under the scanning electron microscope (SEM). In these species, the pollen grains are long-elliptic, goniotreme, reticulate exine ornamentation. The size of pollen grains ranges from 20.3 to 46.7 μm in diameter. Based on the exine ornamentation differentiation, pollen grains are distinctly divided into two types. One is that reticulations have no (or few) granule such as Impatiens siculifer and I. wuyuanensis, the other is that granules are obvious including the other eight species. The results showed that the species of Impatiens can be classified on the basis of the pollen morphology, especially the granule characters of exine ornamentation. The exine sculptures are different among different species and therefore can provide some proof for identification of some species in Impatiens.

Key words: taxonomy, Impatiens L., pollen morphology, scanning electron microscope(SEM)