PEROTIS, in botany: A genus of the digynia order, belonging to the triandria class of plants; and in the natural method ranking under the 4th order, Gramina. There is no clyx: the corolla consists of a bivalvular gluma; the valves are oblong, acute, somewhat unequal, and terminating in a sharp beard: it has three capillary stamens; the antheræ incumbent; the styli capillary, and shorter than the corolla; the stigma feathery and divaricated. The corolla serves as a perianthium, including a single seed of an oblong linear shape.—Of this there is only one species; viz. plumosus, a native of America, and lately introduced into New Garden.