noun
- The movement of plant leaves or other organs in response to the onset of darkness, typically involving closing or folding movements.
Usage: botanical term; also called sleep movement
Examples
- The nyctinasty of tulips causes their petals to close at night.
- Many legume plants exhibit nyctinasty, folding their leaflets when darkness falls.
- Scientists study nyctinasty to understand circadian rhythms in plants.
- The nyctinasty response helps protect delicate flower parts from nocturnal insects and moisture.
- Clover demonstrates clear nyctinasty by closing its leaves in the evening.