It is not enough to post a picture. You need to give the dimensions of the flower and the height of the scapes and then sometimes you can get lucky if your flower has an unusual feature. But it can be impossible. If you care enough to have only identified ones, then give it to a friend that doesn't care and buy a true Siloam's Rare Gem.
I bought one called Atomic Inferno and it came up yellow. I finally was able to identify it as Larry Grace. The next year, it had an Atomic Inferno flower AND a Larry Grace flower. I separated the Atomic Inferno and had two plants but two years later and Larry Grace still has some Atomic Inferno.
http://www.seasidedaylily.com/...
It looks a bit like Party Dress
