Practically the tendrils assist the plant in its native state to scramble over rocks or trees.
Some petioles are long, slender and sensitive to contact, and function as tendrils by means of which the plant climbs; as in the l,' nasturtiums (Tropaeolum), clematis and c in others; and in compound leaves the midrib and some of the leaflets may similarly be transformed into tendrils, as in the pea and vetch.
The tendrils of a vetch and of a cucumber are analogous, and also homologous because they both belong to the category leaf; but they are only analogous to the tendrils of the vine and of the passion-flower, which belong to the category stem.
They climb by means of tendrils, which are stipular structures arising from the leaf-sheath.
The parts of the leaf are frequently transformed into tendrils, with the view of enabling the plants to twine round others for support.