They wondered whether damage to a plant’s leaves could serve as an early-warning sign. Flowers with a memory of leaf damage closed faster and tighterThe results pointed to something more sophisticated than a simple reflex. Fifteen minutes after being touched, flowers on plants with prior leaf damage had closed to significantly smaller angles than those on undamaged control plants. Control plants closed more sluggishly early in the day and more tightly as the morning wore on. The leaves and flowers are entirely separate organs, so the effect can’t be explained by direct injury to the flower itself.