I don't normally pay a lot of attention to the S psittacina flowers as they're so late in the season and there's other things to attract my attention at that time of the season. However, with the mass re-pot this year this one now stares at me when I enter the greenhouse and I attempt to duck the webs.
A quick look and there's something different. A petal out of place perhaps? So I lifted a petal and there's another underneath. Try a different petal and the same result. Both flowers have double petals.