====== Foliar nictinasty ======

//Foliar Nictinasty// (FN) is the tendency for (some) plants to open their leaves during daylight hours and close them at night - tightly following the day/night cycle.

This process has been observed and debated for at least 2,000 years. In 1729 //Linnaeus// suggested that the plants were 'sleeping'. Later, //Charles Darwin// compiled a list of 79 plants which show FN.

Although many of the bio-mechanical mechanisms which control the movements have been identified, modern-day botanists don't as yet have an agreed explanation as to why the opening/closing cycle has evolved - or what benefits it may have for the plant.

Theories include :

  * Reducing nocturnal transpiration
  * Reducing the leaching of minerals from leaves
  * Reducing the need for leaf support tissue
  * Preventing the growth of epiphylls and fungal pathogens
  * Reducing moonlight-induced disruption of photoperiodism
  * Reducing nocturnal herbivore activity

- and many more. See : [[https://onlinelibrary.wiley.com/doi/10.1111/brv.12444|The functions of foliar nyctinasty: a review and hypothesis]] {{:oa_padlock_grn.png?16&nolink|Open Access}}//Biological Reviews//, Volume 94, Issue 1 p. 216-229

//Note: //Complicating the picture, the majority of plants have little or no tendency for FN. And some species , e.g. the //Prayer Plant// (//Maranta leuconeura) //do the exact opposite - opening their leaves at night, and closing them during the day.