June 2, 2022
Fun Fact: Your house plants remember when you left for holiday without watering them, and they are not happy about it.
Researchers at the University of Western Australia have shown that the sensitive plant (Mimosa pudica) can not only learn from experience but can also remember those lessons weeks later. M. pudica, is a perennial plant in the pea family (Fabaceae) and is native to the Caribbean and South and Central America. It is known for its rapid movement where it folds up its leaves as a defence mechanism when touched or otherwise suddenly stressed (nyctinastic movement). You can often find sad little M. pudica plants at nurseries that have been harassed by passers-by. Please rescue them.
The researchers from Australia found that the M. pudica they were studying for an unrelated research question quickly stopped curling their leaves in response to being ‘alarmed’ but not harmed. The authors suggest that this shows that they had learned that folding your leaves in this scenario was a waste of valuable energy. Furthermore, they found that their subjects remembered this lesson and didn’t close their leaves when exposed to the same “scary” situation a month later.
If you are interested in further reading on the M. pudica study, see their paper: Gagliano M et al. 2014. Experience teaches plants to learn faster and forget slower in environments where it matters. Oecologia, published online January 05, 2014; doi: 10.1007/s00442-013-2873-7
For a (satirical) discussion on its implications, follow this link: https://www.youtube.com/watch?v=OKNzlNKyQ1U