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The pollinarium morphologies of 85 species and four subspecies of Hoya were investigated in the present study. The longest pollinium was found in Hoya multiflora , the widest in H. archboldiana , and the smallest in H. bilobata. Pollinium shape showed the widest variation range of all palynological characters, and nine shapes were distinguished in this study. A pellucid margin was present in the pollinium of 84 taxa, and absent in five species. In total, 10 types of pollinarium were recognized based on the following characters: presence/absence of a pellucid margin and the caudicle wing, the ratio of corpusculum/pollinarium length, width/length of pollinium, and curving orientation of the caudicle wings. Types V and X were found in a greater number of taxa compared with the other eight types. Type V is a combination of obliquely elongate or oblong pollinium, presence of a pellucid margin and caudicle wing, and corpusculum length less than half of the pollinium. Type X combines pollinium with variable shapes, a pellucid margin, unwinged and twisted caudicle, and corpusculum with obvious lateral extensions. The characters of 46 taxa with a resolved position in the latest phylogeny of Hoya were mapped and ancestral reconstruction analysis was carried out, indicating that the presence of a pellucid margin in the pollinium, corpusculum length less than half of the pollinium, and rhomboid-shaped corpusculum with lower extensions represent the ancestral state of the genus. Clade II is characterized by the absence of a pellucid margin and twisted caudicles. Loss of the pellucid margin occurring in Clade II and sometimes in other clades is considered independent reversals to the plesiomorphic state. The presence of a pellucid margin and rhomboid corpusculum, and absence of caudicle wings characterizes Clade IV. Ancestral reconstruction analysis revealed that pollinarium type V was the ancestral state of the core lineage Clade V. The species in this clade share presence of both a pellucid margin and caudicle wing, straight caudicle, and pollinium width of 201–300 µm. Clade VI (the largest lineage) as well as Clades I and III have diverse palynological characters, but pollinarium type X and type V is probably the ancestral state of Clades VI and I, respectively. [ABSTRACT FROM AUTHOR]