The pollen morphology of two species of Linaceae-Humirioideae and three species of the genus Erythroxylum has been described. All the specimens studied occurin the southern part of Brazil, except Humiria balsamifera whose pollen morphology has been studied in order to establish the phylogenetic relationships between the species of the two familes. Vantanea and Erythroxylum belong to the same pollen type, but H. balsamifera is different with regard to the apertures and exine stratification.