Premise of research. Early-divergent angiosperms typically possess hermaphroditic flowers but often lack any biochemically mediated self-incompatibility mechanism. Although outcrossing is generally promoted in these taxa by protogyny, which is effective for precluding autogamy (self-fertilization within a flower), other mechanisms are necessary to prevent geitonogamy (self-pollination between different flowers within an individual). In this article we investigate the occurrence and efficacy of inter- and intraindividual floral synchrony for preventing geitonogamy in the early-divergent angiosperm Desmos chinensis (Annonaceae) within the context of the overall floral biology and pollination ecology of the species.Methodology. We assess the floral phenology (at the flower, individual plant, and population levels), floral scent chemistry, pollination ecology, and breeding system of D. chinensis.Pivotal results. Desmos chinensis is pollinated by small Amystrops beetles (Nitidulidae) that are attracted by flor...