Rudbeckia hirta makes up the largest group or black-eyed Susans. Hirta means hairy and you can pick these plants out by their fuzzy, often scratchy leaves. R. hirta is commonly referred to the Gloriosa Daisy, a short lived perennial that is often tender and grown as an annual in northern states. But there's quite a variety of Gloriosa Daisies and they bloom throughout the summer. One you've probably admired is 'Cherokee Sunset' (Rudbeckia x hirta hybrida). This looks more like a Gaillardia (Blanket Flower) than a yellow daisy, with semi-double and double, 2- to 4-inch, flowers in shades of yellow, orange, bronze, and mahogany.