The chief function of velamen tissue is to .....

Explanation

### Step-by-Step Solution:

1. **Understanding Velamen Tissue**: Velamen tissue is a specialized tissue found in the roots of certain plants, particularly epiphytes. It is a characteristic feature of hygroscopic roots.

2. **Identifying Epiphytic Plants**: Epiphytes are plants that grow on other plants for support and space but do not parasitize them. They derive nutrients and moisture from the air and rain.

3. **Types of Roots in Epiphytes**: Epiphytes typically have different types of roots:
- **Clinging Roots**: For fixation to the host plant.
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