First record of bat-pollination in Merremia (Convolvulaceae)

While insects are the dominant pollinators of angiosperms, vertebrate pollinators such as bats and birds play a crucial role in pollinating plants that require cross-pollination. Merremia platyphylla (Convolvulaceae) exhibits floral traits typical of bat pollination (i.e., chiropterophily), including white bell-shaped flowers with crepuscular anthesis and abundant nectar production. These traits suggest that bats are likely the most important pollinators for this species. We investigated the nectar traits, volatile organic compounds, and the pollination and mating system of M. platyphylla to assess whether its floral characteristics align with the chiropterophily syndrome and determine if bats are the most effective pollinator. Although peak nectar production and volatile compounds did not entirely match those expected for bat-pollinated plants, M. platyphylla was effectively pollinated by bats, followed by diurnal pollinators, likely hummingbirds, but not honeybees, since they did not contribute to fruit production. This study provides the first record of bat pollination and floral volatile compounds not only in the genus Merremia, but also in the entire tribe Merremieae. We discuss whether this species is in a stable mixed pollination state or undergoing a transitional phase toward specialized bat pollination, given its generalized pollination system and the mismatch between some floral traits and those typically seen in chiropterophilous plants.