(of the periodic movement of flowers or leaves) caused by nightly changes in light intensity or temperature.‘Leaflets of nyctinastic plants assume a vertical (i.e. closed) position in darkness and revert to horizontal orientation upon illumination.’
- ‘Leaf-movement in nyctinastic plants has long been believed to be controlled by plant hormones that are common among all nyctinastic plants.’
- ‘Several systems of measurement have been used to characterize leaf or leaflet orientation during nyctinastic and heliotropic movement.’
Early 20th century from Greek nux, nukt- ‘night’ + nastos ‘pressed’ + -ic.
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