Chrysopogon zizanioides aka Cuscus Grass

Chrysopogon zizanioides, or vetiver, is a perennial grass. It belongs to the grass family, Poaceae. Its native range runs from northeast India to Indo-China. It grows in warm climates and forms dense, upright clumps. Wild plants grow on floodplains and beside streams and rivers. Other records place it in open, dry sites. It stays evergreen where the climate allows.

Garden plants reach 4–8 feet [1.2–2.44 metres] tall. Clumps spread to 3–4 feet [0.9–1.22 metres] wide. One tropical source gives a shorter usual height. It records plants reaching 10 feet [3 metres] at the extreme. The stiff stems hold long, narrow, green leaves. The leaves have smooth edges and no hairs. One source reports leaves reaching 10 feet [3 metres] long. Fall foliage can turn copper-brown or purple. Below ground, a stout, scented rhizome supports fibrous roots. These roots can reach 13 feet [4 metres] deep.

Summer flowers grow in loose, branched panicles. These brown-purple clusters measure about 0.5 feet [0.15 metres] long. Wind carries the pollen between flowers. The fruit is a small, dry grain with one seed. Gardeners can divide the clumps to make more plants. Sources differ on growth speed, from moderate to fast. NC State lists low upkeep and no major plant problems. Its profile also notes resistance to insect pests.

Vetiver grows best in full sun and moisture-holding soil. It also accepts partial shade and well-drained ground. It grows in clay, loam, and sand. It tolerates acid, neutral, and alkaline soils, plus salt. Established plants withstand drought and brief periods of waterlogged soil. NC State lists USDA zones 8b–10b. Cold tolerance depends on the plant's stage of growth. Tropical data report dormant survival near −15°C. Yet frost at 0°C can badly damage new shoots. Another source warns that hard frosts can kill plants.

Gardeners use vetiver as an accent or in large containers. Its deep roots help hold slopes and limit soil loss. They also help remove excess nutrients and farm chemicals. The plant tolerates many heavy metals in polluted sites. Dense clumps give small animals shelter and draw useful insects. Scented roots supply oil for perfume, soap, and creams. People also use roots for baskets, fans, and thatch. Roots and their oil flavour syrups, sweets, and drinks. Sources record folk medicinal uses, including skin treatments. These uses do not establish proven health benefits. The sources report no known hazards.