Abstract
In Brazil, the genus Pseudobombax is represented by some 120 species occurring in different vegetation types. Bombacoideae species have nocturnal flowers and are bat and hawkmoth visited. The aim of the work was to investigate the reproductive biology of P. marginatum, and to describe the plant-floral visitors relationships. The study was carried out in a Caatinga area in Afrânio municipality, Pernambuco state. Phenology, floral biology, flower-visitor behavior and reproductive system were analyzed. P. marginatum has chiropterophilous flowers, although it is not visited by bats, a fact possibly related to the forest fragmentation process in the study area. The flowering period of the species was from May to July, - floral visitors were hawkmoths, bees, wasps and birds. Nectar production was high with low sugar concentration. Reproductive success was obtained only in cross pollination, due to the incompatibility mechanism. P. marginatum presents a critical situation for regeneration due to the lack of efficient pollination services, caused probably by forest fragmentation in the study area and the lack of chiropterans visitors.
Key words:
forest fragmentation; pollination service; incompatibility mechanism
