Flowering Phenology and Diversity in Tropical Bignoniaceae

Central American Bignoniaceae show five distinct patterns of flowering phenology. Four of these phenological types characterize different bee-pollinated species. Only the generalized "cornucopia" strategy is employed by temperate Bignoniaceae. In the tropics this strategy is also prevalent and is often associated with a seasonal sequence of flowering by related species. The more specialized phenological strategies employed by many tropical species of Bignoniaceae are viewed as making possible differential and essentially contemporaneous attraction of similar pollinators from the same limited pollinator resource. The high diversity of tropical Bignoniaceae appears to be facilitated by use of a variety of phenological strategies by the different species. It is suggested that such mechanisms may be an important factor in maintaining increased tropical diversity in other groups of plants.