Biologia floral e polinização de Arrabidaea conjugata (Vell.) Mart. (Bignoniaceae)

Abstract

This work deals with the floral biology, the foraging activities of floral visitors (pollinators and robbers), phenology and reproductive system of Arrabidaea conjugata (Vell.) Mart. (Bignoniaceae) in the “restinga” of Maricá, Rio de Janeiro, Brazil, from 1997 to 2000. The flowers display daytime anthesis and last only one day. These attractive pink flowers are tubular, hermaphroditic, odoriferous and produce nectar as the floral reward. The nectar is secreted by a nectariferous disk concealed within a chamber. The pollen grains are gradually released throughout anthesis, extending the pollen presentation phase. The bees Euglossa cordata Linnaeus, Centris analis Fabricius and C. tarsata Smith are the pollinator species. Primary and secondary nectar pilferage by several bees, butterflies and a hummingbird is found in A. conjugata. The species is self-incompatible and has low fruit set (Fruit/Flower = 12.2%). Flowering of A. conjugata lasts from December to March (hot, rainy season) with a peak in January. The seeds are anemocoric and dispersal peaks in the cold, dry season.