Biologia da polinização da palmeira tucumã (Astrocaryum vulgare Mart.) em Belém, Pará, Brasil

It was studied some aspects of the pollination biology of fiber palm in experimental station of Embrapa, Eastern Amazon at Belém, PA. Phenology, floral morphology, time of flowering, pollen viability, and floral visitors data were collected, in ten plants, from January to December/1997. This palm is arborescent, multicaule, monoecious with inflorescence involved by a bract woody covered by thorns and hundreds unisexual sessile flowers. The female flower is flanked by two male flowers forming the triads, and located in the base of the rachillae; cream and measure 5 to 10mm of length; campanular type with petals stuck to the stigma exposed. The male flowers is in larger amount, and measure from 2 to 4mm of length. The flowering and fruiting were registered in every period, with picks of March to July and December to March, respectively. The opening of bract and exposition of the inflorescence occurred mainly in the beginning of the morning and in the night, moment in that all the female flowers began the anthesis happening with stigma producing secretion viscous, and stay receptive for 24 at 36 hours. The male flowers, also, presented simultaneous anthesis, staying viable for 24 at 36 hours, but stayed in the rachillae for many days. Pollen viability was high in flower buds in the pre-anthesis and in the open flowers. The floral rewards were the pollen abundantly and stigmatic secretion. Several parts of the inflorescence, mainly the flowers, emitted strong scent. The floral visitors were insects, with predominance of beetles and bees. Therefore the fiber palm is protoginic with high pollen production and strong scent as the primary attractive and prevalently cantharophilic pollination. © 2003, Sociedade Botanica do Brasil. All Rights Reserved