Abstract: The pollen grains of 8 species and 4 varieties of Calamus, 1 species of Plectocomia, 1 species of Daemonorops, and 2 species of Salacca (Palmae ) were examined by light microscopy and scanning electron microscopy. The pollen aperture of Calamus is dicolpate, and its tectum of exine is reticulate, perforate or foveolate. The aperture of D. matgaritae is dicolpate, which differs from the previous report, and its tectum of exine is granulate. The aperture of P. kerrana is dicolpate, and its tectum of exine is reticulate, although the aperture of S. secunda is also dicolpate but its tectum is smooth, sparsely perforate or foveolate. The apertures of S. zalacca is nearly annualocolpate, and its tectum is densely perforate with large supratectal spines. This research shows that pollen morphology can reflect the differences between the species of Calamus. The results also support the previous taxonomical status of : 1) C. balansaeanus var. castaneolepis, C. erectus var . birmanicus, C. palustris var . longistachys as varieties; 2) C. karinensis as independent species. Furthermore , pollen morphology is of important significance to elucidate the relationship between Calamus and its related genera .

Key words: Calamus