Résumé
The genus Riodocea is here described from material collected in the varzea forest of the Rio Doce Valley, northern Espirito Santo. Riodocea is a monotypic genus probably related to the Amazonian endemic Kutchubaea. A line drawing shows general morphology and photomicrographs show pollen morphology of Riodocea pulcherrima. Distribution maps of Riodocea and Kutchubaea are included. The valley of the Rio Doce is here included in the Bahian Hylaea, defined as a subregion of the Brazilian Atlantic forest. The connections between the Amazonian Hylaea and the Bahian Hylaea are discussed.