Palynological study of Plantago major and P. lanceolata in north of Iran

Plantago major L. and P. lanceolata L. are abundantly being found in the north of Iran recognizing as valuable medicinal plants. In this study, populations of these two species from northern parts of the country including Sari, Ziarat, Masouleh and Shurab were collected and a number of qualitative and quantitative traits of their pollen grains were studied and compared using scanning electron microscope (SEM). Pollen morphology of both species showed that, although their pollen grains are monad with small-sized, often prolate-spheroidal, pantoporate, verrucated and granulated ornamentation, but their pore structures are different while P. lanceolata have larger pollen grains and more pores than P. major. The pores of P. lanceolata are small, with annulus and well-defined operculum, whereas the pores of P. major are larger, without annulus and well- or ill-defined operculum. It seems that, their pore structures could be a key trait in the palynological studies. The results suggest that, the palynological results can be effective for these species identification and can help to classification and taxonomy of Plantago L. genus.