The clusioid clade is one of the major subclades identified within the large, diverse rosid order Malpighiales, using molecular data. However, nonmolecular synapomorphies are unclear, and more comparative data are needed to elucidate deep relationships within the order. In this article, pollen and tapetum characters are reevaluated in relation to recent hypotheses of phylogenetic relationships within clusioids. This is done to shed light on the evolution of pollen and tapetum, particularly the evolution of pollen dyads, and also to assess the potential utility of pollen and tapetal characters in the systematics of the clusioids. The comparative morphology of pollen and tapetum is examined in selected taxa from Bonnetiaceae (Bonnetia), Calophylaceae (Caraipa), Clusiaceae (Clusia, Garcinia), Hypericaceae (Hypericum), and Podostemaceae (Podostemum). Pollen and tapetum characters in clusioids and selected outgroups are tabulated, based on both original observations and an extensive literature search, and then...