The Euglenophyceae flora of Lake Amapá I, Rio Branco, Acre State, Brazil, constitutes a contribution to the phycological inventory of the State of Acre. It is based on the study of 15 samples collected with plankton net and by passing an open flask in areas with dense plankton concentrations. Samples were prepared and preserved with Transeau solution. Twenty five taxons were identified. Genera Euglena and Trachelomonas were the most frequently represented.
plankton; taxonomy of Euglenaceae; Acre State