Introduction:

India has been facing the problem of exotic species that were introduced in the country and have become notorious weeds. These species are harmful to the environment and cause damage to the ecosystem.

Exotic Species:

Exotic species are those that are not native to a particular area but are introduced there. They can be plants, animals, or other organisms that are brought from other regions or countries.

Notorious Weeds in India:

Among the exotic species that were introduced in India, three have become notorious weeds. These are:

1. Lantana camara:
Lantana camara is a shrub that was introduced in India as an ornamental plant. However, it has become a notorious weed that is harmful to the environment. It grows rapidly and forms dense thickets that shade out native plants. It also produces toxic chemicals that prevent other plants from growing.

2. Eichhornia crassipes:
Eichhornia crassipes, also known as water hyacinth, is a floating aquatic plant that was introduced in India for its ornamental value. However, it has become a serious problem as it spreads rapidly and forms dense mats on water bodies. This blocks sunlight and oxygen, leading to the death of aquatic animals and plants.

3. Parthenium hysterophorus:
Parthenium hysterophorus, also known as congress grass or carrot weed, is a herb that was introduced in India as a forage crop. However, it has become a notorious weed that is harmful to human health and the environment. It produces allergenic pollen that causes respiratory problems in humans and animals. It also competes with native plants and reduces biodiversity.

Conclusion:

All three exotic species - Lantana camara, Eichhornia crassipes, and Parthenium hysterophorus - have become notorious weeds in India. They are harmful to the environment and cause damage to the ecosystem. It is important to control their spread and prevent the introduction of other exotic species in the country.