Definitely not Joyce Trott - looks more like Jack of Diamonds.

I've Googled it and it certainly seems a good match although someone else has suggested Frances Williams and I am struggling to see the difference between the two!
I'm also nagging the supplier to identify what he actually supplied. Difficult isn't it.

Frances Williams is what's known as a Giant, meaning it is very large, with large leaves - Jack of Diamonds is a medium, whereas Joyce Trott is a small. I don't think its Frances Williams myself.

Thanks for the clarification, Bamboo.

Difficult though, as you say - there are so many similar varieties, so sometimes the only guide is what size they're supposed to be. there's a pretty good site for ID of these - Mickfieldhostas. Thousands of the things...