My green-eyed flowers do look like “Prairie Sun” http://davesgarden.com/pf/go/54909/index.html. After more research, it looks like this is a newer introduction than the old-fashioned ‘Irish Eyes’ http://davesgarden.com/pf/go/49951/index.html. Prairie Sun is the same species as the black-eyed Susan, Rudbeckia hirta, but a different cultivar. It also looks like it will be an annual in my zone (6a). A description I found “The single, daisy flowers are a unique combination of gold and primrose yellow. ‘Prairie Sun’ is the first Rudbeckia with this pattern and a lime green central cone. Slightly later to flower than the old-fashioned ‘Irish Eyes,’ ‘Prairie Sun’ flowers prolifically from mid-summer until the plant is killed by freezing temperatures. The variety is distinctive from a distance due to the lighter pastel flower colours. ‘Prairie Sun’ offers all of the fine Rudbeckia qualities such as tall plants easily grown with little pest damage. ‘Prairie Sun’ is best grown as an annual.” Thanks for the help in identifying this plant.