Flora of the cangas of the Serra dos Carajás, Pará, Brazil: Onagraceae

Abstract The aim of the present study is to investigate the Onagraceae growing on iron-ore substrate (canga) at the Serra dos Carajás, Pará state, Brazil. It comprises identification key, detailed descriptions, comments on the species and their distribution and illustrations. Seven species of Ludwigia were reported for the area, all associated with temporarily or permanently flooded environments.