The pollen morphology of 18 heterostylic species, representing 2 genera, of Cordiaceae from the state of São Paulo were investigated. The pollen grains were acetolyzed, measured, described and photomicrographed under light microscope, and when necessary, under scanning electron microscope. Cordia has 3-colporate pollen grains with long colpus and lalongate endoaperture, the exine is spiny to spinulate-verrucate. Varronia has 3-porate pollen grains and pores with operculum, the exine is reticulated, homobrochate to heterobrochate. In most of the species the pollen grains of the long-styled (pin) flowers have higher diameter values. Although Cordia and Varronia can be easily distinguished based on pollen morphology, both genera are stenopalynous and it is not possible to distinguish species based on pollen grains morphology, though different group of species have pollen grains with different average size, size measures overlap.
Boraginaceae; Cordiaceae; heterostyly; pollen grains
