As result of subtribe Ecliptinae studies from Brazilian Amazonia, is described here a new species, Acmella marajoensis G.A.R. Silva & J.U.M. Santos. At the present moment, this species had been considered as endemic of the Marajó Island. Latin diagnosis, detailed description, taxonomic commentaries and illustrations are presented.
Compositae; Ecliptinae; Acmella; Marajó Island