Enter the name of the cultivar you're looking for into the search box. If you don't know a name, you can try entering descriptive terms. AS IN ALL SEARCH ENGINES, you can limit a multi-word search to exactly the phrase you want by enclosing the phrase in quotes. For example, entering Beni komachi will get hits for all names including 'beni' and and all names including 'komachi', but typing "beni komachi" (in quotes) will get hits only for the name Beni komachi.
At present, this engine will search only for sites in the US that offer a significant variety of cultivars for sale. I hope to develop engines for locating sources in the EU, Japan, and Australia at some point. If you have URLs for sites in the US or elsewhere that should be included, please email them to Gerry.Roe@gmail.com