I guess you can think of this as the inverse of a single lily having multiple cultivar names. That problem is solved using the additional cultivar field.
But what to do when multiple unique cultivars have the same name? For example, there are (at least) two cultivars with the name 'Starburst', two named 'Fanfare', two named 'Salsa' and the list goes on.
I looked at PlantFiles to see how it was done there. It looked like the 'Salsa's were dumped in the same place, though they are totally different lilies. I prefer not to do that. Help!