Fully opened flower of the Mexican primrose-willow (Ludwigia octovalvis)

When I first encountered this sweet yellow delight in roadside ditches, I had no idea how tightly its buds close after sunset. As I watched the bud in my previous image begin to unfurl, I wondered how long it would take for the flower to fully open.

Not being on a schedule, I decided to explore the field around the plant while I waited. As it turned out, the time between my photo of the bud and this photo was forty-four minutes. Even though I missed a few minutes at the start of the process, it still took less than an hour for the flower to unfurl and greet the day.

Of some interest is the fact that none of the buds began to open until touched by sunlight. Even as this flower gleamed, buds still shaded or shadowed remained tightly closed: waiting.

Comments always are welcome.