Eichhornia crassipes: Water Hyacinth
The water hyacinth is thought to be native to tropical America but is nowadays found in all lakes and rivers in the tropics. Though it is a very beautiful plant, it has caused more problems than delight in tropical countries for it spreads very rapidly, thus making water courses unnavigable.
In some places, however, the attitude towards this plant is quite favourable. Round Hanoi, for example, the Vietnamese grow it in ponds enclosed by a floating frame of bamboo to keep the clumps from being scattered by the wind. In these parts eichhornia is important as fodder and practically the only source of food for small Chinese pigs and water buffaloes.
For the European, of course, Eichhornia crassipes will remain a lovely plant for room decoration, floating on the surface of water. Its large root system is spread out underwater, and the spongy leaf stalks are arranged in a rosette on the water’s surface. The leaf blades are orbicular. The, about 8 cm (3 in) across, are produced throughout the year, but chiefly in late summer and autumn.
The water hyacinth may be grown in a paludarium or aquarium and outdoors in a pool in summer. If cool conditions can be provided in winter (temperature of about 5 to 7°C [41 to 45°F]) the plant should be laid loosely on mud. It tolerates warm overwintering too, but in that case the pool must be provided with artificial illumination. Water hyacinths multiply very rapidly by means of side rosettes.