Vetiver (Chrysopogon zizanioides) is a perennial grass of the Poaceae family, native to India. The name comes from Tamil. In western and northern India, it is popularly known as khus (please check Opium_poppy#Use_as_food), giving the earlier English names cuscus, cuss cuss, kuss-kuss grass, etc. Vetiver can grow up to 1.5 meters high and form clumps as wide. The stems are tall and the leaves are long, thin, and rather rigid; the flowers are brownish purple. Unlike most grasses, which form horizontally spreading mat-like root systems, Vetiver's roots grow downward, 2–4 meters in depth. Vetiver is closely related to other fragrant grasses such as Lemon Grass (Cymbopogon citratus), citronella (Cymbopogon nardus, C. winterianus), and Palmarosa (Cymbopogon martinii). Though it originates in India, Vetiver is widely cultivated in the tropical regions of the world. The world's major producers include Haiti, India, Java, and Réunion.   Wikipedia