I don't know of any morning glories that are perennial. Their botancal name is Ipomoea purpurea. I looked at the morning glory packets that I have and I cannot find the exact flower that you show. It will have black seeds of a good size for you to plant next spring. There are some other very pretty ones that you would like I'm sure.
I am beginning to think this might not be a morning glory. The blooms stay open for several days---all day long. Their are no seeds. Believe me I have looked as well as a dozen other people. I lost a dear friend this year and the family wanted me to have the plant because she loved it and they knew I would take care of it.
I will try to get some better pictures in the am. All of the info that I have on the plant came from my deceased friend. It is a perennial because I have watched it for years. The foliage is identical to mg but very large.(4X4) The blooms are in clusters of 3. Each 4". The vine is thick--similar to a Mandavilla.
I believe it is one of the Ipomea acuminatas which are perennial, at least along the coast. They can be quite invasive down here. The colors are amazing however. The pink you have seems to be less common than the electric blue.
Ardesia, I think that you are right. It looks exactly like Ipomoea Acuminata (Blue Dawn). It has the pink veins, flowers are in clusters of 3-4,
and it is a perennial.
These images were taken this am. We had heavey rains yesterday so most of the bloom are on the ground.
Thanks to all of you for your help.