Epinasty (epinastic movements) A nastic movement that involves the curving of a plant organ away from the axis (i.e. downward) as a result of greater growth on the upper surface, as in the opening of flowers.

• 偏上性生长（偏上性运动）：植物开花时由于上表面生长较快而引起植物器官弯曲并偏离轴向的向性运动（如向下）。