Under the name of oil of lemon grass there is imported from Ceylon and other parts of the East an oil much used in perfumery. The source of this oil is according to some authorities andropogon schaenanthus, and according to others A. citratum. A very similar oil is imported from the same localities as the oil of citronelle; it is said by some that these oils differ only in name, and by others that they are distinct and furnished by different species of andropogon. Andropogon is a large genus among grasses, nearly 500 species being enumerated; our native representatives of the genus, known as beard grass, have nothing remarkable about them, but several of the tropical species possess decided aromatic properties in their leaves or roots. In India the roots of one species are woven into mats, which at the same time exclude the sun from apartments and give an agreeable perfume to the air as it passes through them. The plant known in our greenhouses as lemon grass is A. schamanthus; it has leaves which in appearance are not distinguishable from those of any other coarse grass, but when bruised they give off a most agreeable odor, almost precisely like that of the well known sweet-scented or lemon verbena (Lippia [Aloysia] citriodora). The oil of lemon grass is used to make the perfume known as extract of verbena, and it is used in combination in other favorite perfumes, including the finer kinds of cologne water.