nyctinastyn.
/ˈnɪktᵻˌnasti/, U.S. /ˈnɪktəˌnæsti/ Botany.
The tendency of leaves or other parts of a plant to take up different positions at different times, usually in response to regular (esp. nightly) changes in light intensity or temperature. Also: a nyctinastic movement. Cf. nyctitropism n.
ΘΚΠ
the world > plants > part of plant > growth, movement, or curvature of parts > [noun] > nastic movement
nyctinastism1906
seismonasty1912
nasty1924
nyctinasty1936
thermonasty1936
1936 J. B. Hill et al. Bot. ix. 228 Certain leaves as well as flowers may fold up at night. These so-called ‘sleep movements’ of plants, brought about by the alternation of night and day, are the most common nasties and are termed nyctinasties.
1976 P. Bell & D. Coombe tr. Strasburger's Textbk. Bot. (new ed.) 594 Marsilea is the only pteridophyte in which the leaflets exhibit sleep movements (nyctinasty..).
1994 Functional Ecol. 8 384/1 Little is known about the ecological significance of nyctinasty, but other kinds of leaf movements such as heliotropic movements may have a profound influence on plant carbon gain.
This entry has been updated (OED Third Edition, March 2004; most recently modified version published online March 2022).
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n.1936