Word of the week: Nyctinasty

An amazing fact, in biology, is how this science may become wordy (to the point weirdy would even be a more acurate word about it). But we really need to put a word on what we observe afterall… I think therefore a new category of posts of the “word of the week kind” is needed, where I could rant about big words I find while reading. Some of these are nice or even (a)cute words, but are unfortunately rarily used in poems (or should we consider biology being all about poetry?)…

The word that makes me willing to begin with this category is nyctinasty (nyctinastie in French). Nasties (not dynasties!) are words describing plants’ orientation or movements (sure they move!). Sunflower flowers for example turn their head toward the sun all day long, thus following the big star (This is the typical example for plants movements!).

Nyctinasty, it is thus the opening/closing movement occuring at dawn or dusk, which makes open or close leaves from numerous species within Fabaceae.

You can see here leaves of Mimosa pudica, a nyctinastic species closing its leaves during the night. These leaves are also closing when one touches them, probably as a defense, and that’s where the name for the family (not the taxinomic level here!) comes from (“sensitives”). One leaf on the left is actually almost closing here…

We don’t know yet why the Fabaceae are often nyctinastic, but we begin to know about the process itself. It is apparently a question of life or death, since leaves that are treated as to be stay awake have a much shorter lifetime than their control counterparts [1].

Picture is courtesy of: El buitre

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[1]- Ueda, M. and Y. Nakamura. 2006. Metabolites involved in plant movement and ‘memory’: nyctinasty of legumes and trap movement in the Venus flytrap. Natural Product Reports, 23 (4): 548-557