The comparative pollination and floral biology of baobabs (Adansonia - Bombacacee)

The baobabs comprise eight species with large, spectacular, nocturnal flowers. The African baobab, Adansonia digitata, has long been known to be bat-pollinated. In this paper I document the floral biology and pollination systems of the remaining seven species. The two species in section Brevitubae, both endemic to Madagascar, are pollinated by nocturnal mammals (fruit bats and lemurs). In contrast, the five species in section Longitubae, four endemic to Madagascar and one to Australia, are pollinated by long-tongued hawkmoths. In all cases, animals besides the legitimate pollinators also exploited nectar and pollen. The two pollination systems occurring in the genus correlate closely with differences in the floral morphology, phenology, and nectar production.