Abstract
Axonopus fusiformis, a new species of Axonopus sect. Axonopus ser. Axonopus, similar in habit to the widespread and locally sympatric A. purpusii, is described from the Brazilian Pantanal. Diagnostic differences mainly concerning spikelet morphology are discussed and illustrated. Based on the documented occurrence, this new species seems to be the first member of the Poaceae endemic to the Pantanal.