The last two pictures were taken about 1AM. By that time the blooms were fully open and the sepals were fully re-flexed as can be seen in the last picture.
This is the third flush of blooms I have had from these plants this summer. The plants are very old. I have had them myself about 45 years and I continue to root pieces . The original came from my grandmother who spent several years in Florida and brought the original back to Alabama when she returned. I seldom fertilize. I go not repot often. In fact, I leave them in the same pots until the roots eventually crack open the pots. I use plastic pots to decrease the weight of the plants as they get heavier and bigger as they grow. My plants have limbs that are 5/6 feet long and are certainly not graceful. But when they flower, they can be forgiven. In their natural element growing in trees, water drains away quickly and there is not a lot of soil, so keeping them pot bound simulates that environment. It seems to me that letting them get dry and then watering again brings on a new flush of flowers. They are a joy to watch bloom and almost the only care they require in my zone 8 garden is to keep them from freezing.