Epiphytes are characterized by the presence of a specialised tissue in their roots called ……….

Explanation

**Step-by-Step Solution:**

1. **Understanding Epiphytes**: Begin by defining what epiphytes are. Epiphytes are plants that grow on other plants (usually trees) but do not take nutrients from them. They are often found in tropical rainforests and have adapted to live in environments where they can access sunlight and moisture.

2. **Identifying Specialized Tissues**: Recognize that epiphytes have specialized structures that help them survive in their unique habitats. One of these structures is found in their roots.

3. **Defining Hygroscopic Tissue**: Understand that epiphytes have a specific type of tissue that is hygroscopic, meaning it can absorb water from the atmosphere. This is crucial for their survival as they often grow in areas where water is not readily available from the soil.

...