The genus Scutachne (Poaceae, Paniceae) is revised. This American genus, which included two species from the Caribbean, was circumscribed on the basis of morphological and molecular characters. To analyze both species of the genus, S. amphistemon and S. dura, a detailed study of the micromorphology of the upper anthecium and leaf anatomy, together with exomorphological characters, was performed. Both species differ in vegetative and reproductive characters, including blade distribution, ligules, presence of axillary inflorescences, consistency of upper glume, lower lemma, and lower palea, presence of a lower flower, upper anthecium ornamentation, and presence of a rachilla extension. Anatomically, S. dura is a C₄ PCK species, while S. amphistemon is a C₃, non-Kranz taxon. The molecular phylogenetic analysis supports these morphological differences. As a result, we concluded that Scutachne, as presently circumscribed, is a polyphyletic genus. Therefore, the genus is here redefined and S. amphistemon is transferred to the new genus Mayariochloa. Affinities of the new genus with other genera of Paniceae are also discussed.