Bird-pollination and fruiting phenology in Spathodea campanulata Beauv. (Bignoniaceae).
Spathodea campanulata is an evergreen tree species. It blooms and fruits during the dry season. It is an obligate outcrosser requiring pollinators for pollen flow between conspecific trees. Its flowers show a combination of bird and bat floral characteristics suggesting that the flowers are in transitional stage from bat- to bird-pollination. The flowers provide calyx water and nectar for the flower visitors. Birds were the exclusive pollinators. Bees also use the floral rewards but they tend to stay on the same tree day-long and effect self-pollination which is not functional in S. campanulata. Trigona bees die in the calyx water and/or nectar and become a solid bee diet to the visiting birds. Natural fruit set is very low but it is compensated by large seed crop. The fruit is a capsule and dehisces naturally when mature, releasing small, light and winged seeds into the ambient air. Seed dispersal takes place effectively by wind during dry season.