Apparently the flower had opened last night because it looks as if it is closing up completely to drop off. I once had one called Dutchman's Pipe that bore a white lily that would only do so at night and when you checked it every hour you would see that by midnight it would be fully opened with a really strong lovely smell and in the morning it would droop and then in a day or so be lifeless, but the leaves were different to this one they did not have little barbs like this cactus does, but I will put it on a piece of tree branch and see what happens from there.