Xyris is a genus of about 400 species distributed in tropical regions, reaching temperate areas of the Americas and Australia. The Espinhaço Range concentrates a great wealth of Xyris species; the genus is among the richest of monocots occurring in these mountains. This paper presents a new species of Xyris named for its type locality, the State Park of Rio Preto, located in the far northeast of the Diamantina plateau, in the Espinhaço (Minas Gerais). Illustrations of diagnostic characters, a comparison with morphologically related species, as well as information on ecology and phenology of the new species are provided.
campo rupestre; Diamantina plateau; Poales; novelties; evergreen
