Which aquatic weed, known as the "Terror of Bengal", is regarded as one of the…

Concept

An invasive aquatic weed is a non-native water plant that spreads aggressively and disrupts the ecosystem it enters.

Such weeds can form dense surface mats, blocking light and oxygen exchange and interfering with navigation, irrigation and fisheries.

Application

Eichhornia crassipes, commonly called water hyacinth, is a free-floating aquatic plant. In India it has been called the "Terror of Bengal" because of its rapid spread and severe obstruction of water bodies.

Its habitat and invasive growth pattern match both clues in the stem: it is aquatic and exceptionally troublesome.

Contrast

• Lantana camara is an invasive terrestrial shrub, not a free-floating water plant.

• Parthenium hysterophorus is an invasive terrestrial annual herb commonly called Congress grass.

• Cynodon dactylon is a creeping terrestrial perennial grass commonly called Bermuda grass.

Cross-check

Among the offered plants, only Eichhornia crassipes is a free-floating aquatic weed; the habitat clue independently confirms the identification.

Result

Therefore, the required weed is Eichhornia crassipes (water hyacinth).