A new species of Mesosetum (Poaceae: Paspaleae: Arthropogoninae) with a winged rachis from Serra da Canastra, Minas Gerais, Brazil

A new species of Mesosetumwith a winged rachis, only known from Serra da Canastra, Minas Gerais, Brazil, is described and illustrated. The new species ( Mesosetumcanastrense ) is morphologically similar to M. alatum , but it is distinguished mainly by the collar with a continuous line of trichomes( vs. absent or interrupted in M. alatum ), synflorescences 6‒9(‒12) cm long ( vs. 2.2‒3.2(‒7.5) cm long), pedicelswith a truncate apex ( vs. oblique), spikelets with the base surrounded by long appressed trichomes0.8‒1.2 mm long ( vs. glabrous or with short sparse trichomesca. 0.2 mm long) and with an inconspicuous callus ( vs. conspicuous and geniculate), and the lower anthecium neuter( vs. staminate or neuter). Additionally, the two species also differ in geographical distribution, since M. alatum only occurs in the Brazilian state of Mato Grosso.