**Explanation:**

**Exotic Species in India:**

Exotic species refer to plant species that have been introduced to a new region or country from abroad. These species are not native to the region but have been intentionally or unintentionally introduced by humans. In the case of India, many exotic species of natural vegetation have been introduced over the years. Some of the commonly known exotic species in India include:

1. **Eucalyptus:** Eucalyptus trees are native to Australia but have been widely planted in India for their commercial value and fast growth. They are known for their tall stature and aromatic leaves.

2. **Acacia:** Acacia trees, also known as wattles, are native to Australia and have been introduced to India for their timber and ornamental value. They are known for their thorny branches and yellow flowers.

3. **Lantana:** Lantana is a shrub native to Central and South America but has become invasive in many parts of India. It was introduced as an ornamental plant but has spread rapidly and is now considered a weed in some areas.

4. **Bougainvillea:** Bougainvillea is a flowering plant native to South America but has been widely cultivated in India for its vibrant flowers. It is commonly used as a decorative plant in gardens and landscapes.

5. **Pine:** Pine trees, including species like Pinus roxburghii and Pinus wallichiana, are native to regions like the Himalayas and Europe but have been extensively planted in India for their timber and resin.

**Importance and Impact:**

Exotic species have both positive and negative impacts on the native vegetation and ecosystems. They can provide new resources, such as timber or ornamental plants, and contribute to the diversity of the natural vegetation. However, they can also become invasive and outcompete native species, leading to a loss of biodiversity and disruption of ecological balance.

It is important to carefully monitor the introduction of exotic species and ensure that they do not pose a threat to the existing ecosystems. Proper management strategies, such as regular monitoring and control of invasive species, can help minimize the negative impacts and promote the sustainable use of exotic species in India.