Abstract
The new species Aeschynomene eridesii is here described, illustrated and has its geographical distribution discussed, including flowering and fruiting seasons, morphological relationships, and systematic position, besides assessed according to IUCN criteria. This species is endemic of Brazil and known to the states of Mato Grosso, Pará and Tocantins, where it grows in temporarily flooded environments and riverbanks. Diagnostic characters of A. eridesii include the size of leaves, stipules, bracts and flowers, leaflets with eccentric midvein, in addition to loments with long and curved stipe. This new species is compared with A. pluriarticulata and A. scabra, its congeners morphologically similar.