ABSTRACT
Water hyacinth (Eichhornia Crassipes) is an aquatic plant found free floating on water sources like lake, pond and rivers. It is considered as serious threat to bio-diversity. These plants restrict the flow of water and thus reduce the oxygen level (3). Each plant can produce thousands of seed each year and these seeds can remain viable for more than 28 years. The common water hyacinth doubles their population in two weeks. It has both negative and also positive aspects. They have long, spongy and bulbous stalk. The feathery freely hanging roots are purple colour. The plant height may vary from a few inches. It may rise above the water surface as much as 1 m in height. The leaves are 10-20 cm in diameter which floats above the water surface (4) (Figure 14.2).
