Question

Vegetative propagation in water hyacinth takes place by
 (A) Rhizome
 (B) Bulbil
 (C) Leaf bud
 (D) Offset

Answer 1

Hint: Vegetative Propagation is a type of asexual reproduction in which plants reproduce through stem, root, and leaves. The vegetative propagation is carried out by various vegetative propagules such as runner, rhizome, sucker, offset, tuber and bulb. These propagules have the capability to produce new plants.

Complete step-by-step answer:
Eichhornia crassipes: or commonly known as water hyacinth is an invasive aquatic plant that lives freely on the surface of the water.
Water hyacinth propagates vegetatively through offsets. An offset is a short, runner-like branch that usually occurs in aquatic plants. They are the stout horizontal branch that produces leaves above and roots below the water. They can further be propagated by breaking the offset.
The offsets are one of the units of vegetative propagation which produce new offspring of plants. Water hyacinth propagates at a faster rate by offsets thus covering the water surface completely.

Image: Offset formation in Water Hyacinth

Hence, the correct answer is (D). Offset:

Additional information: Water hyacinth is a perennial, free-floating aquatic plant found mainly in tropical and subtropical areas of the world. Water hyacinth bears flowers that produce thousands of seeds annually and these seeds remain viable for 28 years.
Water hyacinth negatively affects the water bodies by growing rapidly which leads to the blocking of sunlight and oxygen levels in the water. This results in retardation of growth or even elimination of various life forms living under the water.

Note: Water Hyacinth was introduced in Bengal, India for their beautiful flowers and distinct shape of leaves. However, they have become an invasive species by growing at a larger rate. These invasive species are now known as Terror of Bengal because they hinder the growth of other aquatic organisms like fishes and plants by restricting sunlight and oxygen. As fishes are the supplement food of people in Bengal, and fast growth of water hyacinth has resulted in the scarcity of food.