In Smilax, stipules are modified into tendrils and leaves show parallel venation.

Answer

### Step-by-Step Solution:

1. **Identify the Plant**: The question refers to *Smilax*, which is a type of monocot plant known for its climbing habit.

2. **Understanding Stipules**: Stipules are small leaf-like structures that are found at the base of a leaf. In *Smilax*, these stipules are modified into tendrils.

3. **Modification of Stipules**: In *Smilax*, the stipules take on a tendril form, which is typically hook-shaped. This modification allows the plant to attach itself to other structures for support as it climbs.

4. **Leaf Structure**: The leaves of *Smilax* exhibit a specific arrangement of veins known as parallel venation. In parallel venation, the veins run parallel to each other along the length of the leaf.

5. **Characteristics of Parallel Venation**: In parallel venation, the vascular bundles are of similar size and are arranged in a way that they do not intersect. This is a common feature in monocot plants, including *Smilax*.

6. **Conclusion**: Therefore, it is true that in *Smilax*, stipules are modified into tendrils, and the leaves display parallel venation.