Pollination ecology of Platonia insignis Mart (Clusiaceae), a fruit tree from eastern Amazon region

The floral biology of bacuri, Platonia insignis Mart., a fruit tree endemic to the Eastern Amazon Region, was investigated in Belem (1 degrees 27'S 48 degrees 29) and in Tracuateua (1 degrees 05'S 46 degrees 54'W), in the eastern region of Para State, Brazil. Among the studied themes are the animal visitors, time of flower opening, nectar volume and sugar concentration (brix), flower morphology, stigma receptivity, pollen grain viability and the reproductive system. The flowers open around 6:00 a.m., showing attractive colors (pink to red) offering pollen and nectar copiously. The reproductive system is allogamous. Two groups of floral visitors were found: birds and insects. The main pollinators were birds of the families Psittacidae (Pionites l. leucogaster, Brotogeris chrysopterus tuipara and Aratinga l. leucophthalmus); Icteridae (Cacicus cela) and Thraupidae (Cyanerpes caeruleus, Ramphocelus c. carbo, Thraupis e. episcopus and Thraupis p. palmarum). Wasps and stingless bees were found gathering pollen, without pollinating the flowers. It is concluded that P. insignis is an allogamous species with an ornithophilous pollination syndrome.