Abstract: In the present study, the pollen morphology of ten species of Impatiens L. in China was observed under the scanning electron microscope ( SEM). In these species, the pollen grains are goniotreme, zygomorphic, 4-colpate, reticulate exine ornamentation. The size of pollen grains is 25.1 - 42.1μm ×151.0 -
311.2μm. According to the shape difference, pollen grains are distinctly divided into three types, i1e. suborbicular type, elliptic type and rectangular type. The length of polar axis, equarorial axis, width of apertures and sp ine, and the shape of pollen are different to some extent among these different species. There is an interrelationship between the pollen morphology and some morphological characteristics, showing the important taxonomic significance. From the point of the aperture of pollen grains, compared with Hydrocera Bl. , which is 3-colpate, Impatiens L. can be regarded as an evolutional genuswithin Balsaminaceae.

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