The actual diameter of this Prayer Plants blossom is 11 mm across the entire blossom. A blossom is very delicate and only last for approximately six hours; mid-mornings is the best time view.
They are nicknamed Prayer Plants because the over-sized (5 or 6-inches long) ladder back leaves fold up when in darkness and open slowly with the morning light.
Most all the Prayer Plants we have had were of a smaller leave variety and had a strong symmetrical blossom of three pedals.
Since I don't have a true macro lens, it is very hard to get a great close-up of blossoms.