I'm not sure why some of his are registered and some are not.
I could be wrong on this statement about the requirement
It's not good practice, but I don't think there is any requirement that a hybridizer register an introduction. The name it is given would be considered a "garden name" and not an actual registered name. Someone else could register a daylily with that same name and this would cause a lot of confusion. The daylily would actually still be considered a seedling and not a named cultivar for most purposes such as for daylily shows. On the lily auction if a daylily is not registered it has to be listed in the seedling section even if the hybridizer sold it with a name.
