Abstract
This study presents 14 specific and infra-specific pioneer citations of the genus Cosmarium for the Brazilian desmid flora. Sixty-three samples of planktonic and periphytic material studied were collected in three Environmental Protection Areas (Rio Capivara, Lagoas de Guarajuba and Litoral Norte), located in Bahia State, northeastern Brazil, during the Summer (January–March 2007 and 2009) and Winter (June–August 2007 and 2009), both in lotic and lentic environments.