Phenology, floral biology and breeding system are described for 14 Piperaceae species at two sites covered by semideciduous forest in southeastern Brazil. Flowering occurred continuously throughout the year, with a peak during the windy months. All species had minute odorous and nectarless flowers visited by insects; five of them showed a substantial degree of self-compatibility, and one was andromonoecious. Seven species were wind pollinated, and three were exclusively pollinated by insects. Flower visitors were mainly hoverflies and bees. (C) 2000 Annals of Botany Company.854455460