Name the vessel-less families of angiosperms.

Explanation

### Step-by-Step Solution:

1. **Understanding Angiosperms**: Angiosperms are flowering plants that typically have vascular tissues, including vessels. However, some families lack these vessels.

2. **Identifying Vessel-less Families**: The question specifically asks for families of angiosperms that do not contain vessel elements.

3. **Listing the Families**:
- **Tetracentraceae**: This family is known for its woody genera and is recognized for the absence of vessel elements.
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