Nyctinasty

Part of speech: noun

Definitions

1. The phenomenon where specific plants exhibit movement of leaves or flowers in reaction to changes in light levels between day and night
2. The adaptive movement of certain plants that involves the repositioning of leaves or flowers in response to varying light conditions experienced during the transition from day to night
3. The response of particular plants in adjusting their leaves or flowers based on the changes in light intensity experienced from day to night

Etymology: "Nyctinasty" is a technical coinage built from two Greek-derived pieces. The first, "nycti-", comes from Greek "nyktos", meaning "of the night," which also gives English words like "nocturnal." The second element, "-nasty," comes from Greek "nastos," meaning "pressed close" or "compressed," and it appears in "-nasty" words that describe movements in plants that are triggered by a stimulus rather than by the direction of that stimulus. Put together, the word names a plant's night-time folding or drooping response. The word is a modern scientific term, not something ancient botanists would have used. Its parts are classical, but the compound itself was assembled by scientists studying plant movement, so the meaning is precise and technical: the plant responds to the change from light to dark, and the movement reflects that change rather than the direction the light came from.

Synonyms: night movement, nocturnal response