Hoya wallachii Flowers Revealed

I decided to take the time to find out more about the night time life of the flowers of Hoya wallachii. I have been constantly frustrated with this plant because by the time I get down to my grow tent in the morning the flowers are pretty much closed up. I took a plant whose buds were going to open very soon and moved it to an upstairs window sill where I could more closely observe it. The flower opened up at night and it never gets beyond a large bell shaped flower. Because of some photos that I have seen online that made the flowers appear to open flat like Hoya patella, I thought that is what they are supposed to do. Those photos from the internet are misleading; they never open beyond a large bell shape during the entire night. They close up during the day and open at night. This goes on for about three days before the flower no longer opens and eventually falls off. Below is a photo of a fully opened flower on Hoya wallachii: