Abstract: In this paper, surface features of seeds in 18 species in the genus Thermopsis R. Br. (Leguminosae) were observed under scanning electron microscope (SEM). Their seed surface was found to be quite well differentiated and to have important taxonomic value. T. alpina, T. barbata, T. inflata, T. lupinoides, T. licentiana, T. smithiana, T. turkestanica had reticulate seed surface; T. californica, T. divaricarpa, T. macrophylla, T. mollis had finely reticulate seed surface; T. gracilis, T. montana, T. fabacea had relatively smooth seed surface; T. alterniflora had irregularly striate seed surface; T. chinensis had mucilaginous seed surface; T. rhombifolia had striate seed surface, and T. villosa had fragmented sculptures on seed surface. Some taxonomi-cally disputable species in Thermopsis can be distinguished by the surface features of seeds.

Key words: Thermopsis R．Br., Surface features of seeds