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

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
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