Common name: Vetiver

Vetiver is an essential-oil yielding grass originating from the Indian subcontinent and Southeast Asia, its natural range extending from Sri Lanka, through southern and eastern India to Myanmar (Burma) and Thailand.

It is an erect, clumping perennial grass typically 1.0 to 1.5 m (3 to 5 ft) tall. At the base are closely spaced leaf sheaths, from which grow light green, slender, erect and rigid leaf blades up to 75 cm (2.5 ft) long. The underground parts consist of branching, spongy rhizomes and deep roots which reach down to depths of up to 4 meters (13 ft), firmly anchoring the plant in the soil.

There are two known varieties of Vetiver, a wild variety from northern India and a cultivated, or so-called southern variety, which is known to flower only rarely or not at all and is the variety discussed here. It is cultivated for its oil mostly in West Java, Reunion and Haiti.

Use

The roots yield on steam distillation an essential oil sold as 'Vetiver Oil'. It is a deep brown, viscous liquid with a long-lasting, sweetly-scented, somewhat woody aroma much valued as a fragrance in perfumery, cosmetics and toiletries, such as colognes, deodorants and soaps. It is especially suited for scenting soaps, due to its chemical stability under alkaline condition.

In perfumery, it is a main ingredients in around a third of high quality western perfumes, including 'Calèche' by 'Hermès', 'Chanel No. 5' by Chanel, 'Dioressence' by Christian Dior and 'Parure' by Guerlain. It is also well represented in men's colognes, such as 'Terre d'Hermes' by Hermès.

About 3000 to 4000 kilograms of fresh roots can be harvested per hectare per year in commercial plantations and with an average oil content of 1% yields 30 to 40 kilograms of oil on distillation, or the equivalent of 27 to 35 pounds per acre.

In its native range, the dried, powdered roots are packaged into small sachets and put into clothing cupboards, both to deodoriser and to ward off moths and other fabric-eating insects.

The roots are also woven into baskets, hand fans and mats that give off a sweet scent, especially when dampened. Woven mats are commonly hung as screens in front of doorways and dampened to cool and scent the air flowing into the house.

Its natural clumping and deep-rooting habit led to its use to protect against soil erosion, especially on exposed hillsides and steeply sloping road shoulders. Clumps are planted in contour rows that trap soil and silt behind them, helping to prevent landslides and the soil from being washed away into streams and rivers.

Health use

The oil has a history of use in traditional medicine as an anthelmintic used for expelling intestinal worms, and as a carminative to prevent gas forming in the gastrointestinal tract, or help with its expulsion. It reportedly possesses stimulant and refrigerant properties.

Climate

Grows naturally in moderately humid tropical lowland climates, generally areas with annual lows of 17 to 25°C, annual highs of 25 to 35°C, annual rainfall of 1000 to 3000 mm and a dry season of 7 months or less.

Growing

New plants are usually grown from divisions of mature clumps, as seed are not always readily available. It performs best on deep free- to slow-draining clay and loam soils of a strongly acid to moderately alkaline nature, generally with a pH of 4.0 to 8.0 and on sites with full to partial sun exposure. It has good tolerance to both drought and waterlogged conditions.

Problem features

It is listed s a weed in at least one reference publication and is recorded as having naturalised in Australia, but there does not appear to be any record of it as a serious weed anywhere in the world, despite its widespread introduction and cultivation. It is assessed as a low weed risk species for Hawaii and Florida, respectively by the Hawaii Pacific Weed Risk Assessment project (HPWRA) and the IFAS Assessment of Non-Native Plants in Florida's Natural Areas.

The leaf blades have sharp rough edges that can cut into skin and flesh.

Books

• Adams, C. D. 1972, Flowering plants of Jamaica, University of the West Indies, Mona, Greater Kingston

• Farooqi, A. A. & Sreeramu, B. S. 2004, Cultivation of medicinal and aromatic crops, Hyderabad University Press, Hyderabad

• Fawcett, W. 1891, Economic plants, An index to economic products of the vegetable kingdom in Jamaica, Jamaica Government Printing Establishment, Kingston

• Hill, A. F. 1952, Economic botany : a textbook of useful plants and plant products, 2nd ed, McGraw-Hill, New York

• Kochhar, S. L 1998, Economic botany in the tropics, 2nd ed, Macmillan India, Delhi

• Macmillan, H. F. 1943, Tropical planting and gardening : with special reference to Ceylon, 5th ed, Macmillan Publishing, London

• National Institute of Industrial Research (India) 2005, Cultivation of tropical, subtropical vegetables, spices, medicinal, and aromatic plants, Delhi, India

• National Research Council (Board on Science and Technology for International Development) 1993, Vetiver Grass: A Thin Green Line Against Erosion, The National Academies Press, Washington D. C.

• Oyen, L. P. A. & Nguyen X. D. 1999, Plant Resources of South-East Asia (PROSEA) 19 : Essential-oil plants, Backhuys Publishers, Leiden

• Randall, R. P. 2002, A global compendium of weeds, R.G. and F.J. Richardson Press, Melbourne

• Randall, R. P. 2007, The introduced flora of Australia and its weed status, Cooperative Research Centre for Australian Weed Management, Glen Osmond, South Australia

• Skerman, P. J. & Riveros, F. 1990, Tropical grasses, Food and Agriculture Organization of the United Nations (FAO), Rome

• Watt, George Sir 1908, The commercial products of India : being an abridgement of the Dictionary of the economic products of India, John Murray, London

Articles, Journals, Reports and Working Papers

• Duke, S. O., Cantrell, C. L., Meepagala, K. M., Wedge, D. E., Tabanca, N., & Schrader, K. K. (2010). Natural toxins for use in pest management. Toxins, 2(8), 1943-1962.

• National Research Council (Board on Science and Technology for International Development) 1990, Saline agriculture : salt-tolerant plants for developing countries, The National Academies Press, Washington D. C.