photonasty


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Related to photonasty: nyctinasty, Seismonasty, thermonasty, Thigmonasty

photonasty

(ˈfəʊtəʊˌnæstɪ)
n, pl -ties
(Botany) a nastic movement in response to a change in light intensity
ˌphotoˈnastic adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

photonasty

the tendency in certain plant species to respond to light by developing sufficient cellular force or growth on one side of an axis to change the form or position of the axis, as in the opening and closing of the flowers of four-o’clocks. Cf. thermonasty.photonastic. adj.
See also: Plants
-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.
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References in periodicals archive ?
The leaflet movements are brought about by motor organs (or "pulvini") localized at the leaflet bases and are induced by transferring leaves from light to darkness (scotonasty) or from darkness to light (photonasty).