Plants also have a touch response called thigmotropism. If you have ever seen a morning glory or the tendrils of a pea plant twist around a pole, then you know that plants must be able to sense the pole. Thigmotropism works much like the other tropisms. The plant grows straight until it comes in contact with the pole. Then, the side of the stem that is in contact with the pole grows slower than the opposite side of the stem. This causes the stem to bend around the pole.
