The movement occurs due to difference in the rate of growth on two opposite sides of a plant organ is called nastic movement. When movement occurs due to faster growth of the upper surface of organ as compare to lower it is called epinasty eg, opening of flower. When movement occur due to faster growth on the lower surface of organ as compare to upper surface it is called hyponasty. Movement which occur due to factors inherent inside the plant body itself are known as autonomic or spontaneous movement.