Desmodium motorium (Telegraph Plant-Rare Plants of Pakistan)

[M Farooq]

That is very interesting ...because the game is that of water. And after reading your explanation now I recall that closure of leaves in the evening is a common trait in many plants of the Leguminoseae (Fabaceae) family e.g. Imli tree is dead in the evening. Some time ago, I was watching a youtube where they showed that Japanese researchers had isolated one compound which was responsible for inducing sleep in such plants i.e. leaf closure. Adding few drops of that compound in the feed water made the plants close their leaves during the day time as well.

But Mimosa & Desmodium are far more complex and therefore fascinating.