The dorsal is 5 cm across, the whole flower barely 6 cm wide. I like it for its natural, wild-type style, but I like the chunky line-bred charlies just as much.
The second flower of that small guy is open now, just in time for a comparison shot with another charlie, which is from US breeding. Its parents are something like 'Half-and-half'x 'Jumbo' and it is certainly not up to its full potential on this small plant yet.