There are a couple of ways I deal with this issue. Neither of them are particularly satisfying, but they do work.
Most plants with large numbers of cultivars have their own custom database page. So, the first method is to go to the custom Black Eyed Susan page ( The Black Eyed Susans Database
) and click Browse the full list of black eyed susans
. That opens a page where all of the species (and subspecies) are listed at the top, sorted alphabetically by species name. The cultivars are listed below the species, sorted alphabetically by cultivar name. It's fairly easy to find what you want that way, because everything is listed in a logical order.
The other method is to do a general database search for Rudbeckia hirta. You'll get a long list with the entry you want buried in there somewhere
. Then, click Control + F on your keyboard, a search box will pop up, type Rudbeckia hirta)
in the box and it will take you to the entry you're looking for. The ")" mark is important. Every entry on the page is going to say Rudbeckia hirta, but only one will have the ")" mark right behind "hirta" (for the rest, hirta will be followed by a cultivar name, variety, etc.).
I'm sure someone else has come up with a smarter, simpler way, but that's what works for me.