The floral biology and pollination by Euglossini bees of an Annonaceae is described for the first time and the adaptations to this mode of pollination are compared with other Annonaceae species that are mainly pollinated by beetles. Unonopsis guatterioides was studied in two "terra firme" forest fragments at the municipality of Manaus (AM). The flowers are protogynous and, remain open during whole anthesis which occurs in two days exposing completely both stigma and stamens. The flowers are visited by male of Eulaema bombiformis (Euglossini) which collect the floral scent; visits of Meliponidae bees and Chrysomelidae beetles were also registered. Unonopsis guatterioides shows synchronous dichogamy.
Annonaceae; floral biology; pollination; Euglossini; Amazon