Nastic Movement

Coral tree saplings fold their leaves down tightly in the evening, and then raise them again to meet the new day. This video shows three days of action taken at one frame every ten minutes. Notice how the leaves start rising before two o'clock in the morning, hours before it starts getting light - indicating that it is controlled by time rather than light. Yet if artificial light is turned on while the leaves are moving down, they start to rise - showing that there is a degree of light sensitivity. During the day the leaves appear to be shaking due to breeze - but it is dead calm and at normal speed no movement can be detected. Night images are iluminated with infra-red.

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