Vetiveria zizanioides (L.) Nash
Khas-khas grass (Africa), vetiver (Europe), lacate violeta.
Tall, stout perennial with an oblong panicle over 30 cm long which has whorled branches bearing spikelets 5-6 mm long, with a few tubercle-based short bristles (Napper, 1965). Under cultivation, the species does not flower (Chippendall, 1955).
Throughout Africa, India, Burma, Sri Lanka, Southeast Asia.
300-1 250 m.
500-5 000 mm in India.
It will grow on sandy loams to clay soils, on strongly acid to slightly alkaline soils with a pH range from 4-7.5, but prefers neutral to slightly alkaline soils.
In India it can be controlled with dalapon at 1117 kg/ha, or bromacil at 17-33 kg/ha (Ray, Agarawala & Fridrickson, 1975).
It stands very heavy grazing, especially in semi-arid areas of India.
It is usually burnt, and the tender regrowth grazed. The older leaves are too harsh for fodder (Gilliland et al., 1971).
Good; it occurs on poorly-drained lands.
2n=20 (Darlington & Janaki, 1945).
The aromatic roots are a source of vetiver oil, used chiefly in perfumery. In some Asian countries the roots are woven into coarse mats and hung in front of doors; they are moistened to cool and scent the air blowing through them (Chippendall, 1955). In India they have been used for matting to give fragrance to a room; they also yield a heavy essential oil, khas-khas or cuscus for perfumery. The roots are also used to provide an important ingredient in curry, khasu-khasu.
It has proved useful for erosion control on 20° slopes in India (Misra, Arnbasht & Singh, 1977) and is one of the most important soil- binding grasses in Fiji (Parham, 1955).