Nyctinasty

[1] Nyctinasty is found in a range of plant species and across xeric, mesic, and aquatic environments, suggesting that this singular behavior may serve a variety of evolutionary benefits.

Many plants use phytochrome to establish circadian cycles which influence the opening and closing of leaves associated with nyctastic movements.

In Albizia julibrissin, longer darker periods, leading to low Pfr, result in a faster leaf opening.

[2] In the SLEEPLESS mutation of Lotus japonicus, the pulvini are changed into petiole-like structures, rendering the plant incapable of closing its leaflets at night.

[3] Non-pulvinar mediated movement is also possible and happens through differential cell division and growth on either side of the petiole, resulting in a bending motion within the leaves to the desired position.

In Lespedeza cuneata the leaf opening factor, potassium lespedezate, is hydrolyzed to 4 hydroxy phenyl pyruvic acid.

Fluorescence studies have shown that the binding sites of leaf opening and closing factors are located on the surface of the motor cell.

[14] The earliest recorded observation of this behavior in plants dates back to 324 BC when Androsthenes of Thasos, a companion to Alexander the Great, noted the opening and closing of tamarind tree leaves from day to night.

Illustration of sleep movements in Medicago leaves, from Charles Darwin 's The Power of Movement in Plants (1880)