I can only say what I would do. Put a string around the one that doesn't belong, around the fans, then when they are done blooming I would dig up the entire clump and separate them. If you do it the lazy way you'll never get all of it and you'll injure the fan.

Any chance it's on the outside of the clump? I've been able to use a sharp knife to cut off an outer fan, but I still had to dig up most of the clump to do it.

Yes, it is indeed on the outside; in fact it is not really touching the other fans at all. I am really tempted to pry it away from the rest of the clump and try not to have to dig up any of Royal Hunter. I'm really not asking about this in an attempt to do this "the lazy way" but If I damage this fan of Chorale Fantasy I'm not too worried as I do have more of it planted elsewhere. I just don't want it growing mixed in with Royal Hunter, which is my favorite of the two. I guess I'm thinking that if it was a large weed I had missed rooting out when it was tiny I certainly wouldn't dig up the whole clump just to remove it! But are you saying I'm likely to leave pieces of Chorale Fantasy's roots behind that will re-grow and cause me grief later on? I have no experience in how well entwined the roots can get in just one year...

Annececilia, I persally would try to do what you're suggesting - just try to lift that side of the plant with a shovel or fork and then see if you can pry/wiggle that fan out without disturbing the rest of the fans and roots too much. If it's only been a year, it shouldn't be too hard, but you won't know 'til you try. I don't think leaving a piece of a root will allow the plant to grow back, except in the case of something like a ditch lily or Kwanso.

Thank you, Twixanddud, for your encouragement. I will definitely do just that. I appreciate your reassurance that if a piece of root breaks off and does get left behind in the clump, that I won't be forever staring at a big, bright coral ruffled daylily growing in the middle of a red daylily clump, LOL!