XVI International Botanical Congess

The role of pollination biology in maintaining species diversity will be addressed by examining a tribe characterized by assemblages of sympatric, locally endemic species. Floral characters (morphology, color, reward, odor),the strata at which flowers are presented (cauliflorously along the trunk, understory/canopy), and phenology appear to be key elements to sustaining the diversity of sympatric Malagasy Bignoniaceae. These findings will be compared with Gentry's findings for neotropical bignons. Colonization patterns within the Coleeae represent major ecological shifts between contrasting environments that correlate with shifts in architectural features (habit, cauliflory) that allow for access of different pollinator and disperser niches. The Malagasy Coleeae represent a rapid divergence from African and Southeast Asian Tecomeae sister taxa. Patterns of diversity and endemism that characterize Malagasy forests may be the result of pollinator relationships and mammal dispersal, as exemplified by the Malagasy Coleeae.