Question

Which weed is known as terror of Bengal? Why it is very difficult to get rid of them form water bodies?

Answer 1

Eichhornia crassipes, commonly known as common water hyacinth, is an aquatic plant native to the Amazon basin, and is often a highly problematic invasive species outside its native range. Water hyacinth is a free-floating perennial aquatic plant (or hydrophyte) native to tropical and subtropical South America. With broad, thick, glossy, ovate leaves, water hyacinth may rise above the surface of the water as much as 1 meter in height. The leaves are 10–20 cm across on a stem which is floating by means of buoyant bulb like nodules at its base above the water surface. They have long, spongy and bulbous stalks. The feathery, freely hanging roots are purple-black. An erect stalk supports a single spike of 8–15 conspicuously attractive flowers, mostly lavender to pink in colour with six petals. water hyacinth reproduces primarily by way of runners or stolons, which eventually form daughter plants. Each plant additionally can produce thousands of seeds each year, and these seeds can remain viable for more than 28 years. Some water hyacinths were found to grow between 2 and 5 metres a day in some sites in Southeast Asia. In their native range these flowers are pollinated by long tongued bees and they can reproduce both sexually and clonally. The invasiveness of the hyacinth is related to its ability to clone itself and large patches are likely to all be part of the same genetic form. These adaptations makes it difficult to get rid of them in water bodies. It was introduced in Bengal in India because of its beautiful flowers and shapes of leaves, but turned out to be an invasive weed draining oxygen from the water bodies and resulted in death of many fish. Fish is a supplement food in Bengal, and because of the fish scarcity in Bengal caused by Eichhornia, the water hyacinth is also called "Terror of Bengal".