SUPPORT
Any of the three plant organs may be modified to support a plant upright or to help it to climb. Prop roots serve the former purpose, tendrils the latter. Tendrils are slender, twining organs, found on climbing plants. They may be modified stems or leaves. As with organs modified for protection, the best way of determining the origin of a modified organ (leaf or stem), is to observe its position relative to the leaves.
PROP ROOTS
Zea (Corn)
Adventitious roots arising from the base of the stem help to support the plant.
Ficus
These are prop roots of Ficus. They function in support of the tree.
TENDRILS
Pisum (pea)
This is a picture of a pea plant.
It has compound leaves with the upper leaflets modified into tendrils. Note the stipules at the base of the leaf.
Passiflora (passionflower)
The tendrils of Passiflora arise in the axils of the leaf. This indicates that they are actually modifed stems.
Here is a close-up so you can see from where the tendrils arise.
SUPPORT