Which of the following plant movements is independent of the direction of the stimulus?

Nastic movements are plant movements that occur in response to a stimulus, but their direction is predetermined by the plant's structure and is independent of the direction of the stimulus. Examples include the opening and closing of flowers (photonasty) or the drooping of leaves of Mimosa pudica (seismonasty).

• Phototropism is growth towards or away from light (directional).
• Geotropism is growth in response to gravity (directional).
• Thigmotropism is growth in response to touch (directional).