There is no such thing as a "correct" or "true" common name. By definition, these vary from region to region, country to country and even plant to plant. The only correct labeling required is the proper botanical name - after that, there is nothing inherently incorrect about referring to any hellebore as a Lenten rose if you wish. Personally, I just refer to them all as 'hellebores' - that's about as generic as you can get :-)

Beware common names! What may be perfectly acceptable in conversation would appear very unprofessional in a nursery or garden center setting. As gardengal48 has indicated, the botanical name is the only correct way to label, especially when you are dealing with a genus so heavily hybridised as helleborus.

Amen to that!