The pollination ecology, the reproductive system and the flowering phenology of Byrsonima gardnerana A. Juss were studied in a Caatinga area of the Parque Nacional do Catimbau, Pernambuco state, Brazil. The species is a shrub with hermaphrodite and zygomorphic flowers, which change color after pollination, with oil as primary floral resource. Flowering pattern is annual, lasting 4-5 months, occurring along the dry season. The species is self-incompatible, has elevated pollen viability and high pollen/ovule ratio. Eleven species of bees were observed visiting the flowers of B. gardnerana, nine of them behaving as pollinators (seven Centris spp.) and two as pollen thieves. Bees of the genus Centris were the most frequent and effective floral visitors, collecting oil and also pollen, in this case vibrating the anthers, always contacting the reproductive structures of the flowers. The flowers of B. gardnerana are, therefore, an important resource to specialized native bees that feed their larvae with floral oils, hence guarantying frequent visits to the flowers.
Caatinga; oil-flowers; phenology; Restinga; self-incompatibility
