We've had this plant(through cuttings) through a few generations of my family. I had found one for sale from a person at a flea market once, but that one died out and never was robust. These pics are from a couple years ago.
The blooms open white and then turn pink over the course of the day, ending as a deep pink flower. Each bloom tends to open in the morning early and only lasts two days at most before curling up.
I don't know exactly what this plant is, where it'd from or what it likes other than rich soil and some water.
This one definitely is not this robust right now. It died back two winters ago when we had some nasty freezes. It does have several stems with leaves popping out now, so I'm hopeful that it'll come back as big and beautiful as ever. Any help IDing it would be appreciated though.