"Five Minutes to Moonflower"

"once you hear it, the idea behind the flower clock is irresistible. First, identify a selection of a few dozen flowers that open and close at regular hours. They can be old friends like lilies, marigolds and primroses. Next, plant them in an organized fashion — perhaps in the segmented shape of a dial or clock face... " what I like about it is it’s so impractical,” he said of Linnaeus’s invention. “One imagines someone waking up in the middle of the night, putting on their dressing gown and then bending over in the garden and smelling the nipplewort and then saying, ‘Wow, it’s late.’ And then going back inside.”"
http://mobile.nytimes.com/2015/01/29/garden/planting-a-clock-that-tracks-hours-by-flowers.html?referrer=

This would be an AWESOME grade school science project.