I Am Curious (Yellow)

We have a very pretty weed, the Bermuda buttercup oxalis, show up every winter here in Southern California. I've shown the world some in What's Up, Chuck?

One of the interesting things about their flowers is that they open when the sun shines on them and they close when they're not getting much light.

I made a movie of a patch of oxalises that are near a large ash tree. The video starts before the sun rises and ends six and a half hours later after the ash shades the flowers. The flowers start tightly shut, they open then close up.

I had my intervalometer set to take a picture every two minutes. I think I should have used a shorter interval. The frames are played back at a rate of 15 frames per second. The six and a half hours are compressed into just 13 seconds.

There was a breeze for much of the time so the flowers jitter a bit but their opening and closing shows up pretty well.