Abstract: Pollen morphology of 18 taxa of Porana s.l. was examined under light microscope(LM) and scanning electron microscope(SEM). Except 7 species and 1 variety, the rest are reported for the first time. The results showed that four types of pollen grains are recognized in Porana s.l. according to the size, shape, ornamentation and characteristics of colpate membranes:(1)subspheroidal of spheroidal (p/E=1.00-1.05), 11.6-15.4×11.4-15.0 um,microspinulose-foveolate or microspinulose-perforate, 3-colpate, coarsely granulate of tuberculate inside the colpi.

Key words: Porana s.l.