nyctitropism

I had a so-called "prayer plant" whose leaves stood up at night. It was a very pretty plant, with variegated leaves with red undersides. However, it was creepy to be studying quietly during the time when the leaves were moving, becase you could hear them move. You'd hear a small swish, and look up, and the plant was wobbling from two leaves having brushed past each other on the way up. Yeesh!