The 25 or so Rudbekia species are all native to North America and Rudbeckia hirta is the state flower of Maryland. We actually have two related varieties of black-eyed Susans in our yard and I don’t know if they are different species or different varieties of the same species. This is by far the more aggressive of the two and left to itself would probably take over the entire yard. In fact, even with some efforts to contain it, it’s taking over the entire yard. On the other hand, there isn’t a lot else blooming right now and if you look into our back yard, it’s filled with yellow, so I can’t really complain. This year, the garden has pretty much had to find for itself. Hopefully we’ll be able to do something with it next year.