And here is a dark form. In my region they grow exclusively in the shade. I think the belief that they are sun plants is not quite correct for all the subspecies.
Superb color Vangelis ! First time I hear the theorie of not growing them in full sun... I tried it in full sun outside and had no flowering... However we must take into account that full sun in Belgium is not tha same as in Greece... 
And shade is Greede is also quite different from shade in Belgium... 
Especially this year, full sun in Belgium was hard to find
. I agree the conditions are different. But the plants I show for sure like moisture and rich conditions. The rhizome is always deep in the soil, even the seed pods are formed even 10cm under ground
