XVI International Botanical Congess

With its conspicuous large red flowers borne before the leaves open, the red silk cotton tree Bombax ceiba is a classic example of ornithophilly. Numerous bird visitors have been recorded by several authors in many areas of its extensive range over S.E Asia and the tree shows the ability to attract a wide range of different birds in different localities. The flowers produce abundant nectar, remain open for 2 to 4 days and can receive many visits. Mammalian visitors were observed with squirrels being a common visitor in Hong Kong, but no bat visitors were seen. Bees and wasps were also frequent visitors to the flowers but pollen transmission was unlikely due to the distance between the anthers and the stigma. The flowers are self-compatible but functionally out-crossing because of the observed herkogamy, though this is reduced in late opening flowers. The particular arrangement of stamens inside the corolla appears to facilitate pollen transmission by birds and differences in pollen fertility between the outer and inner anthers were found.