Pollen morphology of spanishlithospermums.l. (boraginaceae) and its taxonomic significance

The pollen morphology of 12 taxa belonging to four genera of Boraginaceae have been investigated by LM and SEM. The pollen grains vary from genus to genus, and even in some species. In general, the pollen grains are small, isopolar, sometimes subisopolar, colporate with four, five or more apertures; apertural membrane granular. Exine tectate, tectum psilate. The taxonomic implications of the pollen morphological features are discussed.