nyctitropic

American  

[nik-ti-trop-ik, -troh-pik] / ˌnɪk tɪˈtrɒp ɪk, -ˈtroʊ pɪk /

adjective

Botany.

1. tending to assume at or just before nightfall positions unlike those maintained during the day, as the leaves or flowers of certain plants.

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Other Word Forms

• nyctitropism noun

Etymology

Origin of nyctitropic

First recorded in 1875–80; nycti- + -tropic

Example Sentences

Nyctitropism and nyctitropic, i.e. night-turning, may be applied both to leaves and flowers, and will be occasionally used by us; but it would be best to confine the term to leaves.

From Project Gutenberg

The nyctitropic movements of leaves and cotyledons are effected in two ways,* firstly, by means of pulvini which become, as Pfeffer has shown, alternately more turgescent on opposite sides; and secondly, by increased growth along one side of the petiole or midrib, and then on the opposite side, as was first proved by Batalin.**

From Project Gutenberg

There is another difference between the two sets of cases, namely, that there is never, or very rarely, any torsion of the leaves, excepting when a pulvinus is present;* but this statement applies only to periodic and nyctitropic movements as may be inferred from other cases given by Frank.**

From Project Gutenberg

We think that the movement in this case may be called nyctitropic, though the angle passed through was small.

From Project Gutenberg

It deserves notice that seedlings of this and the last-named species were raised at the end of February and another lot in the middle of March, and the cotyledons in neither case exhibited any nyctitropic movement.

From Project Gutenberg