Oplismenus nacreus (Poaceae: Panicoideae), a new grass from Madagascar

Summary A new grass species Oplismenus nacreus from the forests of northern Madagascar is described and illustrated. It is recognisable by the white pearly sheen of its spikelets. It differs from Cyphochlaena and Poecilostachys , as well as from the other species of Oplismenus , by its ovate whitish spikelets and reduced awns not clearly exceeding the spikelets in length. This formal description follows several collecting events in the mid-twentieth century and re-collection by the author in 2011.