I have been spending far too much time watching this plant, and yet it is fascinating... Today it made a new flower, but because it was windy, I didn't get a very sharp image.
So, I simplified it.
I have not been able to identify it, yet I suspect it is quite common. It will start to open a flower in the morning, and roll it up by mid afternoon at the latest. That closed flower will drop off the next day, so it is only open approximately six hours.









