You ask how a reader is to know that the series and trade name is not also the cultivar name. Does it really matter? I don't think most readers care whether the trade name is the same as the cultivar name, and it sometimes is the same.
The true cultivar name can be important to the database admins. Sometimes a series of plants is given a new trademarked series name or trade names by a different company. In those cases, the matching cultivar names let us know that the new name should be treated only as an "also-sold-as" name and does not warrant a new entry.
The system will not process a new plant proposal unless a genus and cultivar are listed. That is why we use the trade name as a place saver for the cultivar name. Using "Unknown" as a place holder would be pointless. We would then have thousands of cultivars named 'Unknown' in our database. It's more useful to use unique cultivar names, different for each plant. Until we know the true cultivar name, we use a place saver that is similar to the trade name, lacking only the copyright or trademark symbol, to aid in database searches.
