Vetiveria zizanioides (L.) Nash
Family
Gramineae
Synonyms
Phalaris zizanioides L., Andropogon muricatus Retzius, Andropogon zizanioides (L.) Urban.
Vernacular Names
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Malaysia |
Nara wastu, akar wangi, kusu-kusu. |
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English |
Vetiver (grass), khus, khus-khus. |
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Indonesia |
Akar wangi (General), larasetu (Javanese), usar (Sundanese). |
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Philippines |
Moras (Tagalog), amora (Cebu), anis de moro (Ilokano). |
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Thailand |
Faek, ya-faekhom, ya-faeklum. |
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Vietnam |
C[of] h[uwl [ow]ng b[af]i, h[uw] [ow]ng b[af]i. |
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French |
Vetyver, chiendent odorant. |
Geographical Distributions
Vetiveria zizanioides grows naturally in swamp areas of northern India, Bangladesh, Burma (Myanmar) and is probably naturalised in many parts of Southeast Asia. It has been cultivated in India for centuries and is now found throughout the tropics and in many subtropical areas. It is grown for its oil mainly in Haiti, West Java, India, Reunion, China and Brazil. To a very limited extent, it is grown commercially as far north as Texas. The use of Vetiveria zizanioides in erosion control spread first from India to the Caribbean and Fiji and later to many tropical areas, including all countries of Southeast Asia.
Description
Vetiveria zizanioides is a coarse, perennial grass that forms large, dense clumps with a stout, compact, aromatic, branched, spongy rhizome and fibrous root system, up to a depth of 4 m. The culm is erect, measures 1-1.5(-3) m tall, 2-8 mm in diametre, terete, solid and smooth.
The leaf sheaths are laterally compressed, measure 10-20 cm long and keeled. The ligule is with a very shallow, fringed rim and measures 0.3-1.7 mm long. The blade is linear, flat or folded, stiff, measuring 30-75(-90) cm x 4-10(-15) mm, hairless below, puberulent in the lower upper side, and scabrous along the edges and back of the midrib.
The inflorescence is a well-exserted, panicle terminal, measures 15-40 cm long, with 6-10 whorls of up to 20 slender bracts while the articulating racemes are up to 10 cm long. The internodes of the racemes and pedicels are slender and slightly thickened apically. The internode of spikelets bear slender rachis which is 5-6 mm long, hairless or with short scattered hairs. The spikelets are in pairs, 1-sessile and 1-pedicelled, 2-flowered and the pair falls as a unit. The sessile spikelet is 3.5-5.5 mm long, with well-developed, pointed, hairless or pubescent callus, with barren lower floret and perfect upper floret. The glumes are chartaceous and bear papillose-based spicules or stiff hairs. The lower glume is lance-shaped, folded about the mid-vein, as long as the spikelet and 7-veined. The upper glume is equal to or slightly shorter than the lower glume. It is 3-veined. The lower floret is with hyaline, ciliate lemma and without palea, while the upper floret is with lance-shaped lemma, measures 3-4 mm long, 1-3-veined, with a short scabrid awn and oblong palea, measures 1.5-2.5 mm long, delicately hyaline, 1-veined and spinulose hairy at the tip. The 3 stamens are with orange anthers about 2 mm long. The pistil is with a hairless ovary and 2 plumose and purple stigmas. There are 2 lodicules which are free and fleshy.
The caryopsis is rarely formed, oblongoid to spindle-shaped and slightly oblique at apex. The pedicelled spikelet is more slender and measures 2.5-4.5 mm long. The lower glume is 3-7-veined while the upper glume is 3-veined. Both florets are staminate or with rudimentary stamens, of which anthers are up to 2.5 mm long.
Ecology / Cultivation
Vetiveria zizanioides is a hydrophyte, often dominant in freshwater swamps, floodplains and on stream banks. It can only survive and spread naturally in swampy areas. It also exhibits, however, xerophytic properties and grows remarkably well under alternating very wet and very dry conditions with annual rainfall ranging from (300-)1000-2000(-3000) mm. Frost is not generally tolerated, but a few selections survive frequent frosts, with extremes as low as -9°C. The average maximum temperature required for good growth is 25°-35°C; absolute maxima may be about 45°C. It should not be shaded permanently, although healthy hedges of V. zizanioides can be maintained in sugar cane plantations, as the plants recover quickly after the harvest of the cane. V. zizaniaides is tolerant of very poor and adverse soil conditions. It is grown on heavy clays and on leached, poor sands. Soil reaction may range from very acid (pH 4.0) to very alkaline (pH 9.6). Mature plants are tolerant of saline soil; yield reductions of 50%(comparable to those of cotton and barley) have been found where salinity in the top 50 cm of the soil was 15-24 mS/cm. It can survive fire, rough trampling and grazing. For the production of Vetiveria zizanioides oil, light sandy soils are required to facilitate harvesting of the smaller roots, which contain most oil.
Line Drawing / Photograph
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References
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Plant Resources of South-East Asia No. 19: Essential-oil plants.
